You just got your salary. Your payslip shows KSh 85,000 gross but KSh 65,000 net. Where did KSh 20,000 go?

PAYE, NSSF, SHIF are all percentages. You need to know how to calculate percentage deductions eating your salary.

Your shop made KSh 100,000 last month. You spent KSh 65,000 on stock. Your profit is KSh 35,000. But how do you calculate percentage profit? Is 35% good or bad compared to competitors?

Your Hustler Fund loan shows 8% interest. Your Fuliza loan costs 1% access fee. Your money market fund pays 16% returns.

Every financial decision involves percentages. You need to know the math.

This isn’t complicated. It’s one simple formula that works for everything. After you learn how to calculate percentage using this method, every other calculation becomes obvious.

The One Formula: How to Calculate Percentage

Percentage = (Part ÷ Whole) × 100

That’s it. How to calculate percentage is just plugging in different numbers.

Part = the smaller amount
Whole = the total amount
× 100 = converts it to percentage

Once you understand this formula for how to calculate percentage, you can calculate percentage profit, percentage loss, percentage increase, percentage decrease, everything.

How to Calculate Percentage Profit For Your Business

Your shop business needs this most.

Understanding How to Calculate Percentage Profit

You bought stock for KSh 60,000.

You sold it for KSh 90,000.

Your profit is KSh 30,000.

How do you calculate percentage profit?

Profit percentage = (Profit ÷ Selling Price) × 100

Profit percentage = (30,000 ÷ 90,000) × 100

Profit percentage = 33%

Now you know how to calculate percentage profit: 33%. That means 33% of every sale stays as profit.

How to Calculate Percentage Profit vs Markup

People confuse these when learning how to calculate percentage profit. They’re different.

How to calculate percentage profit: Based on selling price
How to calculate percentage markup: Based on cost price

Same shop example shows the difference:

If you want to know how to calculate percentage markup:
Markup = (30,000 ÷ 60,000) × 100 = 50%

You marked up the price by 50% from cost.

But when you calculate percentage profit:
Profit = (30,000 ÷ 90,000) × 100 = 33%

Your profit margin is only 33%.

Always calculate percentage profit on selling price for accuracy. That’s the right way to calculate percentage profit.

Also see: Profit margin calculator

Real Kenya Shop Examples: How to Calculate Percentage Profit

Mama Mboga at market:

To calculate percentage profit for her vegetables:

  • Buys vegetables: KSh 5,000
  • Sells vegetables: KSh 7,500
  • Profit: KSh 2,500
  • How to calculate percentage profit: (2,500 ÷ 7,500) × 100 = 33%

Hair salon:

To calculate percentage profit per client:

  • Product cost: KSh 500
  • Service charge: KSh 2,500
  • Revenue per client: KSh 3,000
  • Profit per client: KSh 2,500
  • How to calculate percentage profit: (2,500 ÷ 3,000) × 100 = 83%

Boda rider:

To calculate percentage profit per trip:

  • Fuel per trip: KSh 300
  • Fare charge: KSh 500
  • Profit per trip: KSh 200
  • How to calculate percentage profit: (200 ÷ 500) × 100 = 40%

How to Calculate Percentage In Excel – Step By Step

You don’t need a calculator. Learn how to calculate percentage in Excel if you have data.

Basic Formula: How to Calculate Percentage In Excel

Type this in a cell to calculate percentage in Excel:

=(Part/Whole)*100

Example: Calculate what percentage KSh 2,000 is of KSh 10,000

Cell A1: 2000
Cell B1: 10000
Cell C1: =(A1/B1)*100

Result: 20

Now you know how to calculate percentage in Excel. The formula is simple.

Percentage Format: How to Calculate Percentage In Excel Without ×100

You can also skip the ×100 and use percentage format:

Cell A1: 2000
Cell B1: 10000
Cell C1: =A1/B1

Then:

  1. Right-click cell C1
  2. Select “Format Cells”
  3. Choose “Percentage”
  4. Set decimal places to 2

Result: 20.00%

This is another way to calculate percentage in Excel.

How to Calculate Profit Percentage In Excel

Column A: Cost price
Column B: Selling price
Column C: Profit percentage formula

To calculate percentage profit in Excel:

Row 1:

  • A1: 60000 (cost)
  • B1: 90000 (selling price)
  • C1: =((B1-A1)/B1)*100

Result: 33.33% profit

Copy this formula down to calculate percentage profit for multiple products. Now you can calculate percentage profit in Excel for your entire inventory.

How to Calculate Percentage Increase In Excel

To calculate percentage increase in Excel:

Old value in A1: 50000
New value in B1: 65000
Formula in C1: =((B1-A1)/A1)*100

Result: 30% increase

This is how to calculate percentage increase in Excel quickly.

How to Calculate Percentage Increase – When Things Grow

Your salary went from KSh 50,000 to KSh 60,000.

How do you calculate percentage increase?

Increase = 60,000 – 50,000 = 10,000

Percentage increase = (10,000 ÷ 50,000) × 100

Percentage increase = 20%

Now you know how to calculate percentage increase: your salary increased by 20%.

Formula for how to calculate percentage increase: ((New Value – Old Value) ÷ Old Value) × 100

Real Examples: How to Calculate Percentage Increase

Shop revenue growth:

When you calculate percentage increase in revenue:

  • Last year: KSh 500,000
  • This year: KSh 650,000
  • Increase: (150,000 ÷ 500,000) × 100 = 30% growth

Loan amount increase:

To calculate percentage increase in your limit:

  • Original Hustler Fund limit: KSh 500
  • New limit: KSh 1,000
  • Calculate percentage increase: (500 ÷ 500) × 100 = 100% increase

Your limit doubled.

Salary increase:

When you negotiate and need to calculate percentage increase offered:

  • Current: KSh 60,000
  • Offered: KSh 75,000
  • Calculate percentage increase: (15,000 ÷ 60,000) × 100 = 25% raise

How to Calculate Percentage Decrease – When Things Drop

Shop rent dropped from KSh 15,000 to KSh 12,000.

How do you calculate percentage decrease?

Decrease = 15,000 – 12,000 = 3,000

Percentage decrease = (3,000 ÷ 15,000) × 100

Percentage decrease = 20%

You learned how to calculate percentage decrease: your rent decreased by 20%.

Formula for how to calculate percentage decrease: ((Old Value – New Value) ÷ Old Value) × 100

Real Examples: How to Calculate Percentage Decrease

When you calculate percentage decrease in costs:

M-Pesa expenses dropping:

  • Used to spend: KSh 10,000/month on M-Pesa transactions
  • Now you spend: KSh 7,000/month (using Hustler Fund instead of Fuliza)
  • Calculate percentage decrease: (3,000 ÷ 10,000) × 100 = 30% savings

Business expense reduction:

To calculate percentage decrease in overhead:

  • Transport costs were: KSh 5,000/month
  • Now they’re: KSh 3,000/month (working from home more)
  • Calculate percentage decrease: (2,000 ÷ 5,000) × 100 = 40% reduction

How to Calculate Percentage Discount – Smart Shopping

Shops use this. You need to know how to calculate percentage discount as a customer.

Original price: KSh 10,000

Discount: 20%

How do you calculate percentage discount amount?

Discount amount = (20 ÷ 100) × 10,000 = 2,000

New price = 10,000 – 2,000 = KSh 8,000

Now you know how to calculate percentage discount: you pay KSh 8,000 instead of KSh 10,000.

Quick formula for how to calculate percentage discount: New price = Original price × (1 – Discount percentage as decimal)

New price = 10,000 × (1 – 0.20) = 10,000 × 0.80 = 8,000

Real Kenya Examples: How to Calculate Percentage Discount

Jumia sale:

When you calculate percentage discount:

  • Original price: KSh 5,000
  • Discount: 30%
  • Calculate percentage discount amount: (30 ÷ 100) × 5,000 = 1,500
  • Sale price: KSh 3,500

Shop bulk discount:

To calculate percentage discount on business purchases:

  • Buy KSh 20,000 of goods
  • Get 15% discount
  • Calculate percentage discount: (15 ÷ 100) × 20,000 = 3,000
  • Pay: KSh 17,000

M-Pesa business discount:

When shops calculate percentage discount for digital payments:

  • Service costs KSh 1,000
  • M-Pesa discount: 10%
  • Calculate percentage discount: (10 ÷ 100) × 1,000 = 100
  • Pay via M-Pesa: KSh 900

How to Calculate Percentage Loss: When Business Goes Wrong

Opposite of profit. You need to know how to calculate percentage loss.

You bought stock for KSh 10,000.

You had to sell it for KSh 7,000 (damaged goods, expiry date close).

Your loss is KSh 3,000.

How do you calculate percentage loss?

Loss percentage = (Loss ÷ Cost Price) × 100

Loss percentage = (3,000 ÷ 10,000) × 100

Loss percentage = 30%

Now you know how to calculate percentage loss: you lost 30% of your investment.

Real Examples: How to Calculate Percentage Loss

Vegetable spoilage:

When you calculate percentage loss on damaged goods:

  • Bought tomatoes: KSh 5,000
  • Couldn’t sell all (some spoiled)
  • Sold spoiled cheap: KSh 3,000
  • Calculate percentage loss: (2,000 ÷ 5,000) × 100 = 40% loss

Bad debt:

To calculate percentage loss on unpaid credit:

  • Extended credit: KSh 20,000
  • Customer disappeared (can’t collect)
  • Calculate percentage loss: (20,000 ÷ 20,000) × 100 = 100% loss

Inventory shrinkage:

When you calculate percentage loss from theft/damage:

  • Bought stock: KSh 50,000
  • Theft/loss/damage: KSh 5,000 worth
  • Calculate percentage loss: (5,000 ÷ 50,000) × 100 = 10% loss

How to Calculate Percentage Commission: Get Paid Right

Sales jobs use this. Know how to calculate percentage commission.

You sold goods worth KSh 100,000.

Your commission rate is 5%.

How do you calculate percentage commission?

Commission = (5 ÷ 100) × 100,000

Commission = 5,000

You learned how to calculate percentage commission: you earn KSh 5,000 commission on that sale.

Formula for how to calculate percentage commission: (Commission rate ÷ 100) × Total sales

Real Kenya Examples: How to Calculate Percentage Commission

Real estate agent:

When you calculate percentage commission on property:

  • Property sold: KSh 2,000,000
  • Commission rate: 5%
  • Calculate percentage commission: (5 ÷ 100) × 2,000,000 = 100,000

Agent earns KSh 100,000 on one sale.

Mobile money agent:

To calculate percentage commission on daily volume:

  • Daily transaction volume: KSh 50,000
  • Commission rate: 2%
  • Calculate percentage commission: (2 ÷ 100) × 50,000 = 1,000

Agent earns KSh 1,000 per day just from commission.

Insurance agent:

When you calculate percentage commission on policies:

  • Sold policies: KSh 500,000
  • Commission rate: 8%
  • Calculate percentage commission: (8 ÷ 100) × 500,000 = 40,000

Agent earns KSh 40,000 that month.

How to Calculate Percentage Interest: Know Loan Costs

Critical for loans. Learn how to calculate percentage interest.

You borrowed KSh 10,000 from Hustler Fund at 8% interest for 7 days.

How do you calculate percentage interest?

First, find 8% of KSh 10,000.

Percentage = (8 ÷ 100) × 10,000

Percentage = 800

Wait. That’s 8% for a full year. You’re only borrowing for 7 days.

Daily interest = 800 ÷ 365 = KSh 2.19 per day

7-day interest = 2.19 × 7 = KSh 15.33

So you learned how to calculate percentage interest: you pay about KSh 15 in interest. Not KSh 800.

Real Examples: How to Calculate Percentage Interest

Bank loan:

When you calculate percentage interest on annual basis:

  • Borrowed: KSh 100,000
  • Interest rate: 18% annually
  • 1-year interest: (18 ÷ 100) × 100,000 = 18,000
  • You repay: KSh 118,000 total

Money market fund:

To calculate percentage interest on investments:

  • Invested: KSh 50,000
  • Return rate: 16% annually
  • 1-year return: (16 ÷ 100) × 50,000 = 8,000
  • You have: KSh 58,000 total

M-Shwari loan:

When you calculate percentage interest as fee:

  • Borrowed: KSh 5,000
  • Fee: 9%
  • Calculate percentage interest as fee: (9 ÷ 100) × 5,000 = 450
  • You repay: KSh 5,450 total

Three Types of Percentage Problems: How to Solve Them

Type 1: Finding The Percentage

Question: What percentage is KSh 2,000 of KSh 10,000?

How to calculate percentage: (2,000 ÷ 10,000) × 100 = 20%

Real scenario: Your M-Pesa bill payment is KSh 2,000 out of your KSh 10,000 monthly budget. When you calculate percentage, that’s 20% of your budget.

Type 2: Finding The Part (Given Percentage)

Question: What is 15% of KSh 50,000?

How to calculate percentage amount: (15 ÷ 100) × 50,000 = 7,500

Real scenario: Your salary increase is 15%. Your current salary is KSh 50,000. When you calculate percentage increase amount, your raise is KSh 7,500. Your new salary is KSh 57,500.

Type 3: Finding The Whole (Given Percentage)

Question: KSh 2,000 is 10% of what total?

How to calculate whole amount: 2,000 ÷ (10 ÷ 100) = 20,000

Real scenario: You saved KSh 2,000 this month. That’s 10% of your monthly budget. When you calculate percentage to find the whole, your total budget is KSh 20,000.

Kenya Financial Percentages You’ll See When You Calculate

Income deductions (calculate these from your gross):

  • PAYE (income tax): 5-30% depending on salary
  • NSSF (pension): 6% of salary
  • SHIF (health insurance): 2.75% of salary

Borrowing costs (calculate these before borrowing):

  • Hustler Fund interest: 8% annually (0-14 days), 9.5% if overdue
  • M-Shwari loan fee: 9% facilitation
  • Fuliza access fee: 1% + daily maintenance
  • Bank loans: 12-18% annually

Investment returns (calculate growth potential):

  • Money market funds: 14-18% annually
  • Bank savings: 0-2% annually
  • Treasury bills: 12-16% annually
  • Sacco deposits: 12-15% annually

Business metrics (calculate efficiency):

  • Shop profit margins: 10-40% (depends on industry)
  • Commission rates: 2-10% (varies by role)
  • Stock market returns: -50% to +100% (volatile)

Use our Loan Repayment Calculator when you calculate percentage interest on loans for exact numbers.

Common Percentage Mistakes That Cost Money

Mistake 1: Adding Percentages Wrong

Your salary has multiple deductions. Don’t add them wrong when you calculate percentage total.

  • 8% PAYE deduction
  • 6% NSSF deduction
  • 2.75% SHIF deduction

Total deduction is NOT 8% + 6% + 2.75% = 16.75%

They’re calculated from your gross separately. When you calculate percentage correctly:

Right way:

  • PAYE: 8% of KSh 100,000 = KSh 8,000
  • NSSF: 6% of KSh 100,000 = KSh 6,000
  • SHIF: 2.75% of KSh 100,000 = KSh 2,750
  • Total deductions: KSh 16,750
  • Percentage: 16.75%

It works out the same in this case, but doesn’t always.

Mistake 2: When You Calculate Percentage of a Percentage

Your Hustler Fund loan has 8% annual interest. You borrow for 7 days.

You might think: 8% ÷ 365 × 7 = 0.15%

So when you calculate percentage, you pay 0.15% interest.

Wrong. When you calculate percentage correctly:

Right way to calculate percentage of principal:

  • 8% per year = KSh 8 per KSh 100 per year
  • Per day = KSh 8 ÷ 365 = KSh 0.022 per KSh 100
  • For 7 days = KSh 0.022 × 7 = KSh 0.154 per KSh 100
  • On KSh 10,000 = KSh 0.154 × 100 = KSh 15.40

Mistake 3: Forgetting Base Changes When You Calculate Percentage

Your shop profit went from KSh 50,000 to KSh 75,000 (50% increase).

Then it dropped by 50%.

You’re back to KSh 50,000, right?

Wrong. When you calculate percentage on different bases:

After increase: KSh 50,000 × 1.5 = KSh 75,000

After 50% decrease: KSh 75,000 × 0.5 = KSh 37,500

The 50% decrease is calculated from the higher base (KSh 75,000), not the original (KSh 50,000).

Quick Reference: How to Calculate Common Percentages Fast

To calculate 10%: Divide by 10

  • 10% of KSh 500 = KSh 50
  • 10% of KSh 2,000 = KSh 200

To calculate 5%: Divide by 20

  • 5% of KSh 1,000 = KSh 50
  • 5% of KSh 10,000 = KSh 500

To calculate 25%: Divide by 4

  • 25% of KSh 400 = KSh 100
  • 25% of KSh 8,000 = KSh 2,000

To calculate 50%: Divide by 2

  • 50% of KSh 1,000 = KSh 500
  • 50% of KSh 6,000 = KSh 3,000

To calculate 1%: Divide by 100

  • 1% of KSh 10,000 = KSh 100
  • 1% of KSh 500,000 = KSh 5,000

Real Kenyan Scenarios Where You Must Calculate Percentage

Scenario 1: How to Calculate Percentage for Salary Negotiation

You earn KSh 60,000. Job offers KSh 72,000.

How do you calculate percentage increase in offer?

(72,000 – 60,000) ÷ 60,000 × 100 = 20%

When you calculate percentage, it’s a 20% raise. Good move.

Scenario 2: How to Calculate Percentage for Business Growth

Last year: KSh 500,000 revenue
This year: KSh 650,000 revenue

How do you calculate percentage growth?

(650,000 – 500,000) ÷ 500,000 × 100 = 30%

When you calculate percentage growth, it’s 30%. Solid year.

Scenario 3: How to Calculate Percentage Profit for Your Shop

Cost of goods: KSh 65,000
Selling price: KSh 100,000
Profit: KSh 35,000

When you calculate percentage profit:

Profit percentage = (35,000 ÷ 100,000) × 100 = 35%

For every KSh 100 sold, you keep KSh 35 as profit.

Scenario 4: How to Calculate Percentage Interest on Loans

KSh 100,000 loan at 18% for 24 months.

When you calculate percentage interest total:

Annual interest = 100,000 × 0.18 = KSh 18,000

2-year interest (simple) = 18,000 × 2 = KSh 36,000

When you calculate percentage over 2 years, you pay KSh 36,000 to borrow KSh 100,000.

Use our Compound interest Calculator to calculate percentage interest accurately with compound interest.

Scenario 5: How to Calculate Percentage Returns on Investment

You invested KSh 50,000 in money market fund at 16% for 6 months.

When you calculate percentage returns for 6 months:

6-month interest = (16 ÷ 100) × 50,000 × (6 ÷ 12)

6-month interest = 0.16 × 50,000 × 0.5

6-month interest = 4,000

When you calculate percentage returns, your money grows to KSh 54,000 in 6 months. That’s a free KSh 4,000.

FAQ: How to Calculate Percentage – Your Questions Answered

How do I calculate percentage on a basic calculator?

Most calculators have a % button. But you can also calculate percentage this way:

  • Type the number
  • Press ÷
  • Type 100
  • Press ×
  • Type the percentage you want

Example: To calculate 15% of 1,000:
1,000 ÷ 100 × 15 = 150

How do I calculate percentage if it’s a decimal?

Same formula to calculate percentage. Just use the decimal.

To calculate 5.5% of KSh 10,000:
(5.5 ÷ 100) × 10,000 = 550

Can I use the same formula to calculate percentage for non-money things?

Yes. Anything with a “part” and a “whole” lets you calculate percentage.

Growth rate, inflation, discounts, test scores, business margins; use the same formula to calculate percentage for all of them.

What’s the difference between how to calculate percentage increase vs percentage points?

20% = a ratio (20 out of 100)

20 percentage points = a specific change

If interest went from 5% to 25%:

  • It increased by 20 percentage points (25 – 5)
  • It increased by 400% when you calculate percentage increase ratio (20 ÷ 5 × 100)

Watch out. When people use these interchangeably, they mean different things.

What’s the simplest way to calculate percentage profit?

(Profit ÷ Selling Price) × 100

This is the correct way to calculate percentage profit.

Cost: KSh 60,000
Selling price: KSh 100,000
Profit: KSh 40,000
Calculate percentage profit: (40,000 ÷ 100,000) × 100 = 40%

What’s the formula when I need to calculate percentage loss?

(Loss ÷ Cost Price) × 100

This is how to calculate percentage loss.

Cost: KSh 10,000
Sold for: KSh 7,000
Loss: KSh 3,000
Calculate percentage loss: (3,000 ÷ 10,000) × 100 = 30%

Related Tools & Calculators

Official & Research Resources:

Disclaimer: Percentages and calculations provided are for educational purposes. Always verify with official sources for financial decisions. Interest rates, loan terms, and investment returns change regularly — check with providers for current rates.

Real talk: Percentages control your money. PAYE takes a percentage. Loans cost a percentage. Your investment grows by a percentage. Your business profit is a percentage. Once you learn how to calculate percentage correctly, you control the math instead of the math controlling you. Learn it today.

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