Percentage Calculator

Calculate percentages, percentage increases and decreases, tax amounts, interest share, investment returns, and percentage differences with simple formulas and real financial examples.

How to Use This Percentage Calculator

Percentages are used in personal finance, banking, taxes, insurance, budgeting, investing, and shopping. This calculator helps you solve the most common percentage questions in one place.

You can use it to calculate sales tax, determine how much of your mortgage payment is interest, find the percentage increase in your income, estimate investment growth, compare loan offers, and measure changes in expenses or account balances.

Percentage Formulas

• Percent of a number: x = (p / 100) × n
• What percent is a of b: p = (a / b) × 100
• a is p% of what number: n = a / (p / 100)
• Percentage increase: ((new - old) / old) × 100
• Percentage decrease: ((old - new) / old) × 100
• Increase a number by p%: new = old × (1 + p / 100)
• Decrease a number by p%: new = old × (1 - p / 100)
• Percentage difference: |a - b| / ((a + b)/2) × 100

Find the Missing Percentage, Base Amount, or Result

Enter any two values to calculate the third. This is useful for tax, fees, down payments, interest charges, discounts, and investment returns.

Finance example: If a loan origination fee is 2% of a $3,000 loan, the fee is $60.

Another example: If $240 is 12% of your tax bill base, the original taxable amount is $2,000.

What Is p% of n?

Use this calculator to find a percentage of any amount. This is one of the most common finance calculations.

Finance example: What is 12% tax on a $850 purchase? Answer: $102.

Mortgage example: What is 5% of a $400,000 home price? Answer: $20,000, which may represent a down payment or fee estimate.

Investment example: What is 8% of a $15,000 investment? Answer: $1,200 annual return before taxes and fees.

a Is What Percent of b?

Use this calculator to find what percentage one amount represents of another amount.

Mortgage example: If total mortgage interest paid is $54,000 and total payments are $300,000, then interest is 18% of total payments.

Credit card example: If you paid $75 in interest on a $1,500 balance, that interest charge is 5% of the balance.

Budget example: If rent is $1,800 and monthly income is $6,000, rent is 30% of income.

a Is p% of What Number?

Use this calculator when you know the result and the percentage, but need to find the original amount.

Tax example: If sales tax is $24 and the tax rate is 8%, the pre-tax price is $300.

Commission example: If an agent earns $450 as a 3% commission, the sale amount is $15,000.

Investment example: If you earned $600 and that represents a 4% return, the original investment was $15,000.

Percentage Increase or Decrease from One Value to Another

Use this calculator to compare old and new values, such as income, expenses, account balances, stock prices, or insurance premiums.

Income example: If monthly income rises from $5,000 to $5,500, the increase is 10%.

Investment example: If a stock rises from $40 to $46, the increase is 15%.

Expense example: If your credit card balance drops from $2,000 to $1,600, the decrease is 20%.

Increase or Decrease a Number by a Percentage

Use this calculator to apply a percentage increase or decrease to a value directly.

Salary example: If your annual salary of $60,000 increases by 10%, the new salary is $66,000.

Savings example: If a $20,000 investment grows by 7%, the new value is $21,400.

Debt example: If a $5,000 credit card balance decreases by 15%, the new balance is $4,250.

What Original Number Increased or Decreased by p% Equals the Result?

Use this calculator to reverse a percentage change and find the original amount.

Income example: If your salary after a 10% raise is $66,000, your original salary was $60,000.

Investment example: If an account grows to $10,800 after a 20% gain, the original value was $9,000.

Loan example: If a debt balance becomes $850 after a 15% reduction, the original balance was $1,000.

Difference, Percentage Difference, and Percent Change

Use this calculator to compare two values and measure their absolute difference, percentage difference, and change direction.

Loan comparison example: Compare two lenders offering fees of $2,400 and $2,700 to see the dollar difference and percentage difference.

Investment example: Compare returns of $8,500 and $9,300 to measure how far apart they are.

Expense example: Compare monthly utility bills of $220 and $260 to analyze cost changes.

Common Financial Percentage Examples

1. How much is 12% tax?

To calculate 12% tax on a purchase, multiply the purchase price by 0.12. For example, 12% of $250 is $30. The total price becomes $280.

2. What percentage of mortgage payments is interest?

If total mortgage payments are $300,000 and total interest paid is $54,000, then interest is 18% of the total paid. Use the formula: (interest ÷ total payments) × 100.

3. What is a 10% increase in income?

If your monthly income is $4,500 and it increases by 10%, the increase is $450, and your new monthly income is $4,950.

4. Credit card interest example

If your credit card balance is $2,000 and monthly interest adds $40, then the interest charge is 2% of the balance for that month.

5. Investment return example

If you invest $10,000 and the account grows to $10,800, your gain is $800, which is an 8% return.

6. Discount and sale example

If an item costs $500 and is reduced by 15%, the discount is $75 and the new price is $425.

FAQ

How do you calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number. Example: 12% of 500 = 0.12 × 500 = 60.

How do you find what percent one number is of another?

Divide the first number by the second number and multiply by 100. Example: 50 is what percent of 200? Answer: (50 ÷ 200) × 100 = 25%.

How do you calculate percentage increase?

Subtract the old value from the new value, divide by the old value, and multiply by 100.

How do you calculate percentage decrease?

Subtract the new value from the old value, divide by the old value, and multiply by 100.

What is percentage difference?

Percentage difference compares two values using their average as the base: |a - b| ÷ ((a + b) / 2) × 100.

References

• U.S. Consumer Financial Protection Bureau (CFPB): https://www.consumerfinance.gov/
• Investor.gov – U.S. Securities and Exchange Commission: https://www.investor.gov/
• IRS – Internal Revenue Service: https://www.irs.gov/
• USA.gov Money and Credit: https://www.usa.gov/money

These official resources may help you verify tax rates, loan terminology, credit topics, and investment basics.