Percentages Explained Simply
Learn what percentages really mean, how to find a percentage of any number, and how to work out percentage increase and decrease — with everyday examples.
Percentages pop up everywhere — sale signs, phone battery, exam results, tax. Once you get the core idea they become second nature.
What IS a Percentage?
"Per cent" literally means "per hundred". So 25 % just means 25 out of every 100.
Imagine a pizza cut into 100 tiny slices. If you eat 25 of them, you've eaten 25 % of the pizza. Simple.
Finding a Percentage of a Number
The golden trick:
From there you can build any percentage:
- 5% = half of 10%
- 20% = 10% × 2
- 1% = divide by 100
- 15% = 10% + 5%
Worked Example 1 — Finding 15% of £80
- 10% of £80 = £80 ÷ 10 = £8
- 5% = half of £8 = £4
- 15% = £8 + £4 = £12
Percentage Increase & Decrease
A shop has a jumper for £60 with a 20% off sale. How much do you pay?
Worked Example 2 — 20% off £60
- 10% of £60 = £6
- 20% = £6 × 2 = £12 discount
- You pay £60 − £12 = £48
Worked Example 3 — Percentage Increase
Your rent was £800 and goes up by 5%. What's the new rent?
- 10% of £800 = £80
- 5% = £80 ÷ 2 = £40
- New rent = £800 + £40 = £840
Converting Between Fractions, Decimals & Percentages
| Fraction | Decimal | Percentage |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/4 | 0.25 | 25% |
| 1/5 | 0.2 | 20% |
| 3/4 | 0.75 | 75% |
| 1/10 | 0.1 | 10% |
To convert a fraction to a percentage: divide top by bottom, then multiply by 100.
To convert a percentage to a decimal: divide by 100 (move the dot two places left).
Try It Yourself
- Find 30% of £150. (Answer: £45)
- A phone costs £400 and is reduced by 15%. What do you pay? (Answer: £340)
- Convert 3/8 to a percentage. (Answer: 37.5%)
Want to check your answers or calculate more complex percentages?
→ Open the Percentage Calculator