Percentage Increase Calculator

What Is a Percentage Increase Calculator?

This free percentage increase calculator covers every type of percentage change calculation in four modes — finding the percentage increase or decrease between two values, calculating a new value after a percentage change, working backwards to find the original value before a percentage was applied, and finding what percentage one value is of another. Whether you are tracking price changes, calculating salary increases, analysing business performance, or working on a maths problem — this percentage increase calculator has everything you need.

How Is Percentage Change Calculated?

• Percentage change: % Change = (New − Original) ÷ |Original| × 100. A positive result is an increase; negative is a decrease. Example: price rises from $80 to $100 → (100-80)/80 × 100 = +25%.
• New value after change: New Value = Original × (1 + % ÷ 100). Example: $200 increased by 15% → 200 × 1.15 = $230.
• Original value before change: Original = Current ÷ (1 + % ÷ 100). Example: current price $115 after 15% increase → 115 ÷ 1.15 = $100.
• B as percentage of A: % = B ÷ A × 100. Example: 350 is what % of 500? → 350/500 × 100 = 70%.

How to Use This Percentage Increase Calculator

• % Change mode: Enter original and new value. Get the percentage increase or decrease with sign (+/-), absolute difference, and step-by-step working.
• New Value mode: Enter original value and percentage change (use negative for decrease). Get the new value after applying that percentage.
• Original Value mode: Enter the current value and the percentage that was applied. Get the original value before that percentage change.
• Difference % mode: Enter base value A and comparison value B. Get B expressed as a percentage of A.

What Your Result Means

The result from this percentage increase calculator is shown with a colour-coded hero panel — green for increases, red for decreases, blue for neutral calculations. The percentage sign is preceded by + for increases and – for decreases. The absolute difference (the raw numerical change) is shown alongside the percentage change so you have both the relative and absolute view of the change.

Is This Percentage Increase Calculator Accurate?

Yes — this percentage increase calculator uses standard mathematical formulas and displays results to 4 decimal places. All four modes are mathematically exact for the inputs provided. The original value calculation (reverse percentage) is exact: if you apply 25% to $100 to get $125, then calculating the original from $125 at 25% returns exactly $100.

How to Choose Your Inputs

• % Change mode: The original value cannot be zero (division by zero). Negative original values are supported — the formula uses the absolute value of the original.
• New Value mode: Enter a negative percentage for decreases (e.g. -10 for a 10% decrease). The result correctly shows a value lower than the original.
• Original Value mode: Enter the percentage that was already applied — not the target percentage. If a price increased by 20% and you want to find the pre-increase price, enter 20 (not -20).

Is This Percentage Increase Calculator Suitable for Shopping?

Yes — comparing prices, calculating sale discounts, and checking whether a “deal” is genuine are perfect uses for this percentage increase calculator. Enter the original price and sale price in % Change mode to see the actual discount percentage. Use New Value mode to calculate the sale price for any discount percentage. Also see the Discount Calculator on this site for specific sale price and savings calculations.

Is This Percentage Increase Calculator Suitable for Finance?

Yes — percentage changes are fundamental to finance. Year-on-year revenue growth, portfolio returns, salary increases, inflation adjustments, and interest rate changes all require percentage change calculations. This percentage increase calculator handles all of them. The Original Value mode is particularly useful for calculating pre-tax prices, pre-inflation values, and the original cost before a markup was applied.

Can I Use This Percentage Increase Calculator for Salary Negotiations?

Yes — enter your current salary and proposed new salary in % Change mode to see the percentage increase being offered. Or enter your current salary and your desired percentage increase in New Value mode to calculate what your new salary should be. Knowing the exact percentage helps you negotiate from an informed position and compare offers from different employers on equal terms.

Common Mistakes With Percentage Calculations

• Percentage points vs percentage change: A rate rising from 10% to 15% is a 5 percentage point increase but a 50% percentage change. They measure different things — this calculator shows the percentage change (relative).
• Adding and subtracting percentages directly: A 20% increase followed by a 20% decrease does NOT return to the original — it results in a 4% loss. 100 × 1.20 = 120, then 120 × 0.80 = 96. Calculate each change separately.
• Using the wrong base for reverse percentage: To find the original price before a 20% markup, divide by 1.20 — NOT subtract 20% from the current price. $120 ÷ 1.20 = $100, not $120 − $24 = $96.
• Confusing % of with % more than: 150 is 50% MORE than 100 — but 150% OF 100. These are different calculations. Use the appropriate mode in this percentage increase calculator.
• Rounding intermediate steps: Rounding percentages during calculation introduces errors. This percentage increase calculator uses full precision throughout and rounds only the final display.

Limitations of This Percentage Increase Calculator

This percentage increase calculator performs single-step percentage calculations. For compound percentage changes (e.g. 5% growth per year for 10 years), use the Compound Interest Calculator on this site. It does not perform percentage point calculations — only relative percentage changes. Results are rounded to 4 decimal places for display but calculated with full floating-point precision.

Percentage Increase Calculator — Frequently Asked Questions