How to Calculate Percentages Easily: Practical Guide with Examples (2026)
You spot a jacket at £120 marked "30% off" — how much will you actually pay? Your boss offers a 4% raise on your £32,000 salary — what's your new take-home? Percentages pop up everywhere, yet most of us reach for our phones the moment the maths gets real.
This guide gives you the essential formulas, worked-out examples relevant to UK and US daily life, and a direct link to our free percentage calculator to check your results instantly.
Example 1: Calculating a Shop Discount
During Black Friday, you find trainers priced at £95 with a 20% discount.
Discount: 95 × 20 ÷ 100 = £19 off
Final price: 95 − 19 = £76. Quick shortcut: for 20%, just divide the price by 5.
Example 2: Understanding VAT on Purchases
The UK standard VAT rate is 20%. You buy electronics listed at £200 excl. VAT.
VAT: 200 × 20 ÷ 100 = £40
Price incl. VAT: 200 + 40 = £240. Remember: food and children's clothing are zero-rated in the UK. For US readers, sales tax varies by state (0-10.25%). Use our VAT calculator for instant results.
Example 3: Working Out a Salary Raise
Your annual gross salary is £32,000 and you receive a 4% raise.
Raise: 32,000 × 4 ÷ 100 = £1,280
New gross: £33,280/year. After Income Tax and National Insurance, your take-home will depend on your tax code. Check our salary calculator and percentage calculator for a full gross-to-net breakdown.
Try Our Free Calculator
Skip the mental maths — use our free online percentage calculator for instant, error-free results. Handles discounts, markups, and percentage changes in one click.
Mental Maths Shortcuts
- 10%: move the decimal one place left. 10% of £85 = £8.50
- 25%: divide by 4. 25% of £60 = £15
- 15%: find 10% then add half. 15% of £80 = £8 + £4 = £12
Frequently Asked Questions
What is the formula for calculating a percentage?
Divide the part by the total, then multiply by 100. For example: 45 out of 180 = (45 ÷ 180) × 100 = 25%.
How do I calculate a discount percentage?
Multiply the original price by the discount rate and divide by 100. Subtract the result from the original price. Example: £80 at 30% off → 80 × 30 ÷ 100 = £24 off → final price: £56.
How much of my salary goes to tax in the UK?
Divide the amount deducted by your gross salary and multiply by 100. With a Personal Allowance of £12,570 and the Basic Rate at 20%, an earner on £30,000 pays roughly 13% in Income Tax plus NICs. Use our income tax calculator for your exact figure.
Also check our inflation calculator to see how price rises affect your purchasing power in 2026.