Pay rise from £30,000 to £31,200
Percentage change between two salaries.
Inputs
- Type
- Percentage change
- From
- 30,000
- To
- 31,200
Results
- Result
- 4.00%
((31,200 − 30,000) ÷ 30,000) × 100 = 4%.
Everyday calculators
Percentage Calculator
15% of 80 is 12. For UK VAT at 20%, multiply by 1.2 to add or divide by 1.2 to remove. Use % change for rises and falls.
Last updated: · Rates checked against official sources: · Written and checked by Aivora Digital
Percentages pop up everywhere: discounts, tax, tips, exam scores and growth rates. This free percentage calculator covers the everyday sums you’re most likely to need in one place.
You can work out X% of a number, what percent one number is of another, the percentage change between two values, and reverse percentages. It’s handy for shopping, budgeting and quick checks at work.
The maths all runs in your browser, and the numbers you enter aren’t tracked. For UK VAT at fixed rates, the dedicated VAT calculator is quicker.
Work out a percentage
Results
Result12.00
15.00% of 80.00
Worked examples
Examples you can read without entering anything. Use your own figures for a personal estimate.
15% of 80
The default “what is X% of Y” calculation.
Inputs
- Type
- X% of a number
- Percentage
- 15%
- Of number
- 80
Results
- Result
- 12.00
15% of 80 = 80 × 0.15 = 12.
18 is what percent of 90?
Part ÷ whole × 100.
Inputs
- Type
- Is what percent
- Part
- 18
- Whole
- 90
Results
- Result
- 20.00%
Increase from 50 to 65
Percentage change between two values.
Inputs
- Type
- Percentage change
- From
- 50
- To
- 65
Results
- Result
- 30.00%
((65 − 50) ÷ 50) × 100 = 30%.
Price now £80 after 20% off
Reverse percentage — find the original before a discount.
Inputs
- Type
- Reverse percentage
- Final amount
- 80
- Percentage change
- −20%
Results
- Original amount
- 100.00
£80 ÷ 0.8 = £100. For 20% UK VAT on a VAT-inclusive price, divide by 1.20 instead — or use the VAT calculator.
Pay rises and inflation
To find the percentage size of a pay rise, use percentage change: a rise from £30,000 to £31,200 is 4%. To find the new salary from a percentage, use X% of a number and add it on: 3% of £30,000 is £900, so the new salary is £30,900.
Whether a rise beats rising prices depends on inflation over the same period. With a 4% rise and inflation of 2.9% (ONS CPI in the 12 months to July 2026), your pay buys about (1.04 ÷ 1.029) − 1 = 1.07% more, not 1.1%. The inflation calculator does this for longer periods. Tax and National Insurance take a share of the rise too; the take-home pay calculator shows what reaches your bank.
Discounts, sales and VAT
25% off £60 is £60 × 0.75 = £45. Two discounts in a row don’t add up: 20% off and then a further 10% off is 0.8 × 0.9 = 0.72 of the original price, a 28% discount, not 30%.
For a “was/now” price, use reverse percentage: if a coat is £80 after 20% off, the original was £80 ÷ 0.8 = £100. VAT works the same way: to take 20% VAT out of a price, divide by 1.20 rather than subtracting 20%. The VAT calculator shows net, VAT and gross side by side.
Percentage change or percentage points?
When a rate itself changes, there are two ways to describe it. If a mortgage rate goes from 4.5% to 5.5%, that is a rise of 1 percentage point, but a 22.2% increase in the rate. Neither is the change in your payment: on a £250,000 repayment mortgage over 25 years, the monthly payment goes from £1,389.58 to £1,535.22, a 10.5% rise. The mortgage calculator shows the payment for any rate.
The same applies to Bank Rate. A move from 4% to 4.25% is 0.25 percentage points, or a 6.25% increase in the rate. News reports almost always mean percentage points.
Common percentage mistakes
A 50% fall followed by a 50% rise doesn’t get you back to where you started. £100 falls to £50, and 50% of £50 is only £25, so you end at £75.
Percentages of different bases can’t be added. A 10% rise followed by a 10% rise is 21% in total (1.1 × 1.1 = 1.21), not 20%.
Official sources & further reading
Check rates, bands and eligibility on these official pages before you rely on a figure.
Frequently asked questions
How do I calculate X% of a number?
Multiply the number by X and divide by 100. 15% of 80 = 80 × 0.15 = 12.
How do I work out a percentage increase, such as a pay rise?
((new − old) ÷ old) × 100. A rise from £30,000 to £31,200 is a 4% increase.
What is a reverse percentage?
Finding the original amount before a percentage change. If a price after 20% off is £80, the original is £80 ÷ 0.8 = £100.
What is the difference between a percentage and a percentage point?
A rate going from 4.5% to 5.5% has risen by 1 percentage point, which is a 22.2% increase in the rate itself. News reports about interest rates usually mean percentage points.
Do two discounts add together?
No. 20% off and then 10% off is 0.8 × 0.9 = 0.72 of the price, a 28% discount in total.
Can I use this for VAT?
Yes for simple sums, but remember to divide by 1.20 to remove 20% VAT. The UK VAT calculator labels net, VAT and gross for you.