Interest calculator

An online percentage calculator will help you quickly calculate the percentage of a number, find out the percentage, increase or decrease a number by a percentage.

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Find the percentage of a number
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Increase or decrease a number by a percentage
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What percentage does one number make of another?
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Find a number by percentage

Interest calculator

An online percentage calculator will help you quickly calculate the percentage of a number, find out the percentage, increase or decrease a number by a percentage.

Find the percentage of a number

Calculate what percentage one number is of another

Council:

  • Press Enter to calculate
  • Results update automatically as you type
  • Negative numbers are not supported

About the interest calculator

An online percentage calculator helps you calculate the percentage of a number, find out the percentage and change the number to a given percentage. Suitable for calculating discounts, taxes, profits and other everyday tasks.

Examples of calculations

Let's look at practical examples of using the interest calculator for various tasks:

Percentage of number

Find 20% of the number 500

20% of 500 = 500 × 0.20 = 100

Result: 100

Percentage

25 is what percentage of 200?

25 ÷ 200 × 100% = 12.5%

Result: 12.5%

Number by percentage

If 15% is 30, find the original number

30 ÷ 0.15 = 200

Result: 200

Increase by percentage

Increase 1000 by 15%

1000 + (1000 × 0.15) = 1000 + 150 = 1150

Result: 1150

Decrease by percentage

Decrease 800 by 10%

800 - (800 × 0.10) = 800 - 80 = 720

Result: 720

Complex calculation

Product price 2000₽, 20% discount, then 18% tax

2000 - 20% = 1600₽, then 1600 + 18% = 1888₽

Final price: 1888₽

How Interest is Calculated

The calculator uses standard formulas for calculating percentages: percentage of number (number × percentage ÷ 100), percentage (part ÷ whole × 100), increase/decrease by percentage (number ± number × percentage ÷ 100).

Basic functions

Instant settlements

Results are calculated automatically as you enter data

Multiple Modes

4 different types of interest calculations in one calculator

High accuracy

Accurate calculations with decimal support

Mobile version

Responsive design for easy use on all devices

Advantages

Fast and accurate interest calculations, simple interface, support for various types of calculations, multilingual, free to use.

Tips for use

Use the Enter key for quick calculations, check that numbers are entered correctly, and use a dot for decimals.

Frequently Asked Questions

How to calculate percentage of a number?

To calculate the percentage of a number, use the formula: number × percentage ÷ 100. For example, 20% of 500 = 500 × 20 ÷ 100 = 100.

How to find the percentage of two numbers?

To find the percentage, use the formula: (smaller number ÷ larger number) × 100%. For example, 25 of 200 = (25 ÷ 200) × 100% = 12.5%.

How to increase a number by a percentage?

To increase a number by a percentage, use the formula: number + (number × percentage ÷ 100). For example, increase 1000 by 15% = 1000 + (1000 × 15 ÷ 100) = 1150.

How to reduce a number by a percentage?

To decrease a number by a percentage, use the formula: number - (number × percentage ÷ 100). For example, reduce 800 by 10% = 800 - (800 × 10 ÷ 100) = 720.

How to find the original number if the percentage and the result are known?

To find the original number, use the formula: result ÷ (percentage ÷ 100). For example, if 15% is 30, then the original number = 30 ÷ 0.15 = 200.

Whether it is possible to use the calculator for the calculation of the discount?

Yes, the calculator is great for calculating discounts. Use the 'decrease by percentage' mode to calculate the discounted price.

How to calculate tax using a calculator?

To calculate tax, use the 'increase by percentage' mode. For example, for VAT 20%: price + 20% = price with tax.

Is it possible to calculate profit as a percentage?

Yes, use the 'percentage' mode to calculate profitability. For example, a profit of 50,000 rubles from a turnover of 200,000 rubles = 25%.

How to work with decimal percentages?

The calculator supports decimal percentages. For example, 12.5% ​​of 1000 = 1000 × 12.5 ÷ 100 = 125.

Is it possible to calculate compound interest?

For compound interest, use the calculator step by step: first calculate the percentage of the amount, then add it to the original amount.

How to calculate the percentage of plan completion?

Use the 'percentage ratio' mode: actual result ÷ planned indicator × 100%. For example, plan 1000, fact 850 = 85%.

Can I use a calculator to calculate loan interest?

Yes, the calculator is suitable for calculating simple interest on a loan. For compound interest, a specialized loan calculator is recommended.

How to calculate growth percentage?

To calculate percentage growth, use the formula: ((new value - old value) ÷ old value) × 100%. For example, growth from 100 to 120 = 20%.

Is it possible to calculate the percentage of the amount including tax?

Yes, first calculate the amount with tax (increase by percentage), then find the percentage of this amount.

How to work with negative percentages?

Negative percentages mean decrease. Use the 'reduce by percentage' mode with a positive percentage value.

Is it possible to calculate the percentage of salary?

Yes, the calculator is suitable for calculating income taxes, pension contributions and other salary deductions.

How to calculate the percentage of the deposit amount?

Use the 'percentage of number' mode to calculate interest on the deposit. For example, 5% per annum from 100,000₽ = 5,000₽ per year.

Is it possible to calculate a percentage of the cost of an item?

Yes, the calculator is suitable for calculating trade margins, discounts, taxes and other transactions with goods.

How to calculate percentage of area?

Use the 'percentage of number' mode to calculate a fraction of the area. For example, 30% of 100 m² = 30 m².

Is it possible to calculate the percentage of time?

Yes, the calculator is suitable for calculating percentage of time. For example, 25% of 8 hours = 2 hours.

How to calculate percentage of volume?

Use the 'percentage of number' mode to calculate part of the volume. For example, 15% of 1000 liters = 150 liters.

Is it possible to calculate the percentage of weight?

Yes, the calculator is suitable for calculating percentage of weight. For example, 10% of 50 kg = 5 kg.

How to calculate percentage of quantity?

Use the 'percentage of number' mode to calculate a portion of a quantity. For example, 20% of 100 pieces = 20 pieces.

Is it possible to calculate a percentage of the order amount?

Yes, the calculator is suitable for calculating discounts, taxes, tips and other operations with the order amount.

How to calculate the percentage of the cost of services?

Use the calculator to calculate taxes, discounts, commissions and other operations with the cost of services.

Is it possible to calculate the percentage of income?

Yes, the calculator is suitable for calculating taxes, contributions, alimony and other deductions from income.

How to calculate the percentage of expenses?

Use the calculator to calculate portions of expenses, savings, overspending and other expense transactions.

Is it possible to calculate the percentage of investment?

Yes, the calculator is suitable for calculating investment returns, losses, commissions and other investment transactions.

How to calculate the percentage of turnover?

Use the calculator to calculate part of turnover, margin, profitability and other business indicators.

Is it possible to calculate the percentage of revenue?

Yes, the calculator is suitable for calculating taxes on revenue, commissions, reserves and other transactions with revenue.