Percentage Decrease Calculator
From £120 to £90 is a 25% decrease. Type your two values; the calculator shows the change, the formula, and the working.
The mirror of the increase calculator. Defaults: 120 to 90 = 25% decrease.
How it works.
Formula: ((Original − New) ÷ Original) × 100.
How to calculate percentage decrease, step by step:
- Subtract the new value from the original value: Original − New.
- Divide that drop by the original value.
- Multiply by 100 to express it as a percentage.
Worked example — from £120 to £90: (120 − 90) ÷ 120 = 0.25, × 100 = 25% decrease. Common UK contexts: sale price reductions, pay cuts, real-terms losses to inflation, regional house-price falls.
Worked examples
£100 to £75 = 25% off — a quarter-off sale.
£250,000 to £237,500 = 5% — the kind of HPI fall a region can see in a stressed market.
£35,000 to £33,250 = 5% pay cut — furlough-era reduction.
£20,000 to £19,400 = 3% real-terms loss — what 3% inflation does to spending power if your income is flat.
£199 to £132.66 = 33.33% off — a third-off retail discount, common at end-of-line clearance.
4.75% to 4.50% = 5.26% relative rate cut — a 0.25 percentage point BoE base-rate cut translates to a ~5.3% relative drop in the headline rate.
£12,000 deposit to £8,400 = 30% drawdown — what a 30% emergency-fund tap looks like in pounds.
VAT-inclusive £120 to £100 = 16.67% removal — not a 20% removal; that's why the VAT-remove calculator divides by 1.20.
Premium Bond rate 4.40% to 4.00% = 9.09% reduction — relative drop when NS&I cuts the prize fund rate.
Sources:
ONS CPI
· retrieved 2026-05-12.
Frequently asked questions
How do you calculate a percentage decrease?
Subtract the new value from the original, divide by the original, multiply by 100. From £120 to £90 is (120 − 90) ÷ 120 × 100 = 25% decrease.
How do I work out a percentage reduction or sale price?
Same calculation. A £100 jacket reduced to £75 is (100 − 75) ÷ 100 × 100 = 25% off. To go the other way (find the pre-sale price from the sale price and the % off), use the reverse percentage calculator.
How do I decrease a number by a percentage?
Multiply by (1 − percent ÷ 100). To decrease 200 by 15%, multiply 200 × 0.85 = 170. To decrease 80 by 5%, 80 × 0.95 = 76.
What is the percentage decrease formula?
((Original − New) ÷ Original) × 100.
If I add 20% then take 20% off, do I get back to the start?
No. Adding 20% to 100 gives 120; taking 20% off 120 gives 96. The reverse percentage calculator gets you back exactly.
Can a decrease be over 100%?
No. The most you can decrease something is to zero (100% off). 'More than 100% off' would imply a negative price.
How do I work out the percentage off when I know both prices?
Subtract the sale price from the original, divide by the original, multiply by 100. £80 down to £60: (80 − 60) ÷ 80 × 100 = 25% off. The same calculation works for any pair of UK prices, GBP or pence.
How do I find the original price from a sale price and discount %?
Divide the sale price by (1 − discount ÷ 100). If something is £60 after 25% off: 60 ÷ (1 − 0.25) = 60 ÷ 0.75 = £80 original. Use the reverse-percentage calculator for this exact lookup.
What's the difference between percentage decrease and percentage points decrease?
Decrease is relative; percentage points are absolute. A tax rate falling from 7% to 5% is a 2 percentage point drop but a 28.57% relative decrease ((7 − 5) ÷ 7 × 100). Always state which one you mean — UK news regularly conflates them.
Why does my real-terms cut look bigger than the inflation rate?
Because real-terms loss compounds. If inflation is 3% per year and your income is flat for 2 years, you've lost roughly 5.91% in real terms (1 − 1/(1.03²)), not 6%. Use the inflation-impact calculator for compounding over multiple years.
Common mistakes when calculating percentage decrease
(1) Using the new value as the denominator instead of the original. (2) Confusing 'percentage off' with 'percentage of the original you keep' — if 25% is off, you pay 75%. (3) Stacking discounts incorrectly: 50% off then extra 20% off is 60% off the original, not 70%.