Percentage Increase Calculator

Percentage increase = (new − old) ÷ old × 100. To apply: new = old × (1 + increase% ÷ 100).

How to calculate a percentage increase

A percentage increase measures how much a value has grown relative to where it started. Take the difference between the new and old figures, divide by the old figure, and multiply by 100. The “divide by the old value” step is the one people forget — the increase is always measured against the starting point, not the ending one. So a rise from 200 to 250 is a 50 ÷ 200 = 25% increase, not 50 ÷ 250 = 20%. If instead you know the percentage and want the new value, multiply the original by one plus the rate as a decimal: 200 raised by 25% is 200 × 1.25 = 250.

This calculator does both. In find mode, enter the old and new values to get the percentage increase, the absolute change, and the multiplier. In apply mode, enter a value and a percentage to get the new figure. Either way it shows the multiplier — a +20% increase is the same as multiplying by 1.2 — which is the quickest way to chain increases or reverse them.

Worked examples: A salary rising from $50,000 to $57,500 → (57,500 − 50,000) ÷ 50,000 × 100 = 15% increase. Applying a 15% raise to $50,000 → 50,000 × 1.15 = $57,500. A price up from $80 to $100 is a 25% increase (×1.25).

Raises, price rises and growth rates

The same calculation answers a surprising range of everyday questions. For a pay rise, the percentage increase tells you how much better off you are relative to your old salary — useful for comparing offers or judging whether a raise keeps pace with inflation. For pricing, it quantifies a price hike from the customer’s point of view, or lets a business apply a planned markup to a cost. For growth tracking — revenue, users, population, followers — the year-over-year percentage increase is the standard way to express the pace of growth on a comparable basis, whatever the starting size.

Because the increase is always relative to the base, the same absolute gain is a bigger percentage for a smaller starting value: adding 100 customers is a 100% increase from 100 but only 1% from 10,000. That is exactly why percentages are useful for comparison — they normalise for size — and why a headline growth percentage means little without knowing the base it grew from.

Stacking increases — they multiply, not add

When increases come one after another, they compound rather than add. Two consecutive 20% rises are not a 40% increase — they are a 44% increase, because the second 20% applies to the already-larger amount (1.2 × 1.2 = 1.44). The same logic drives compound growth: a value growing 10% a year for three years is up not 30% but about 33%. Use the sequential-increases option under advanced to chain several rises and see the single equivalent percentage.

This also explains why reversing a percentage increase needs care. To undo a 25% increase you divide by 1.25 (a 20% decrease), not subtract 25% — because the increase and the matching decrease are measured against different bases. The multiplier shown here makes both directions straightforward: multiply to apply, divide to reverse.