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Algebra

Percentage Increase Calculator

Find percent increase between numbers. Free online Percentage Increase Calculator for algebra — instant, accurate results, mobile-friendly, no signup needed.

Increase
30%

Derivation

  1. ├── 01Givena = 100, b = 130
  2. ├── 02Formula{let t=e.a;return(e.b-t) / t × 100}
  3. ├── 03Substitute{let t=e.100;return(e.130-t) / t × 100}
  4. └── 04Compute Increase30
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§01What is

Understanding the Percentage Increase Calculator

The Percentage Increase Calculator computes Increase from 2 inputs: original, increased to. Find percent increase between numbers.

Algebra is the art of solving for the unknown. Rearranging a formula to isolate the variable you actually need is the single most common real-world math skill — and doing it with real numbers under time pressure is where errors happen. The Percentage Increase Calculator sits in that toolkit — it find percent increase between numbers. Enter your numbers above and the result updates instantly; every step of the math is shown in the Derivation panel so you can see exactly how the answer was reached.

§02The Formula

How it’s calculated

{let t=e.a;return(e.b-t) / t × 100}

Where

a
Original
b
Increased to
§03Practical Example

Step-by-step walkthrough

Scenario

Apply the formula to a realistic set of inputs: Original = 100, Increased to = 130.

  1. 01Start by noting the input — Original: 100.
  2. 02Start by noting the input — Increased to: 130.
  3. 03Substitute these values into the formula: {let t=e.a;return(e.b-t) / t × 100}
  4. 04Compute Increase: the calculator returns 30.
  5. 05Cross-check the answer by opening the Derivation panel above — every line of math is shown so you can follow the computation end-to-end.
§04Variants

Common Percentage Increase Problems

The formula gets rearranged depending on which variable you need. Here are the patterns you’ll run into in the real world — find the one that matches your problem and follow the worked steps.

01 · PATTERN

Original halved

a = 50 (from 100)

Keep every other input at its default and halve the original. See how increase responds.

  1. 01New Original: 50
  2. 02Baseline Increase: 30
  3. 03New Increase: 160
  4. 04Increase increases by 433.3% → use this sensitivity to plan for real-world variation.
02 · PATTERN

Original doubled

a = 200 (from 100)

Keep every other input at its default and double the original. See how increase responds.

  1. 01New Original: 200
  2. 02Baseline Increase: 30
  3. 03New Increase: -35
  4. 04Increase decreases by 216.7% → use this sensitivity to plan for real-world variation.
03 · PATTERN

Increased to halved

b = 65 (from 130)

Keep every other input at its default and halve the increased to. See how increase responds.

  1. 01New Increased to: 65
  2. 02Baseline Increase: 30
  3. 03New Increase: -35
  4. 04Increase decreases by 216.7% → use this sensitivity to plan for real-world variation.
04 · PATTERN

Increased to doubled

b = 260 (from 130)

Keep every other input at its default and double the increased to. See how increase responds.

  1. 01New Increased to: 260
  2. 02Baseline Increase: 30
  3. 03New Increase: 160
  4. 04Increase increases by 433.3% → use this sensitivity to plan for real-world variation.
§05FAQ

Frequently asked questions

Yes. The calculator implements the standard formula as documented and returns exact floating-point results. No approximations are used unless noted in the formula.
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