Calculators & everyday math
How to Increase a Number by a Percentage
Adding a percentage to a number — a 3% price rise, a 12.5% bigger batch, a 25% stretch target — takes two steps, or one if you use a multiplier. This guide shows both methods, how to chain several increases, and how to check the answer.
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Two steps: find the increase, then add it
- Find the percentage of the starting value: 15% of 200 is 200 × 15 ÷ 100 = 30.
- Add it to the starting value: 200 + 30 = 230.
One step: use a multiplier
Increasing by a percentage is the same as multiplying by 1 + percentage ÷ 100. A 15% increase multiplies by 1.15, a 3% increase by 1.03, and a 100% increase by 2. So 200 × 1.15 = 230 in a single step — handy on a phone calculator or in a spreadsheet formula such as =A1*1.15.
| Increase | Multiply by | 200 becomes |
|---|---|---|
| 5% | 1.05 | 210 |
| 12.5% | 1.125 | 225 |
| 25% | 1.25 | 250 |
| 50% | 1.5 | 300 |
| 100% | 2 | 400 |
| 150% | 2.5 | 500 |
Several increases in a row
Chained increases multiply rather than add. Three 10% increases multiply by 1.1 × 1.1 × 1.1 = 1.331 — a total increase of 33.1%, not 30%. Starting from 200, the value becomes 220, then 242, then 266.2.
Check your answer
- The new value should be bigger than the start, unless the percentage is 0.
- An increase under 100% gives less than double; over 100% gives more than double.
- Divide the new value by the start: 230 ÷ 200 = 1.15 confirms a 15% increase.
Increase by a Percentage FAQ
- What is the formula to increase a number by a percentage?
- New value = starting value × (1 + percentage ÷ 100). For 200 and 15%: 200 × 1.15 = 230.
- How do I add 20% to a number?
- Multiply it by 1.2. 45 plus 20% is 45 × 1.2 = 54.
- Are two 10% increases the same as one 20% increase?
- No — together they make 21%, because the second 10% applies to the already increased value.
- How do I increase a number by a percentage in a spreadsheet?
- Multiply by the multiplier: =A1*(1+B1/100) if B1 holds the percentage as a plain number such as 15, or =A1*(1+B1) if B1 is formatted as a percentage.
- What does a 100% increase mean?
- The value doubles: the amount added equals the starting value.
Related guides
- Increase vs. ChangeAdding a known percentage to a value and measuring how much a value grew are different calculations. How to tell them apart and which to use.
- Pay, Prices, and MarkupWorked percentage increases for pay rises, price rises, and scaled recipes, why markup and margin differ, and how to undo an increase.
Open the tool
Jump into Percentage Increase Calculator when you are ready to process your files.
