Ratio Calculator
Compare and simplify ratios, or solve for an unknown term in a ratio. Free online Ratio Calculator for math — instant, accurate results, no signup needed.
Derivation
- ├── 01Given
A = 3, B = 4, C = ?, D = 20 - ├── 02Formula
A/B = C/D → C = A × D / B - ├── 03Substitute
3 × 20 / 4 - ├── 04Missing C15.0000
- └── 05Simplify A:B
GCD(3, 4) = 1; A:B = 3 : 4
Ratios appear in the earliest Greek mathematics (Eudoxus, 4th century BCE) as a way to compare incommensurable lengths without a concept of irrational numbers.
Understanding the Ratio Calculator
The Ratio Calculator helps you compute compare and simplify ratios, or solve for an unknown term in a ratio.. It runs entirely in your browser with no sign-up required.
Mathematics shows up in every corner of daily life — budgeting, cooking, construction, engineering, even reading a bus schedule. A calculator like this lets you skip the scratch-paper step and move straight to the answer, without the arithmetic mistakes that creep in when the numbers get messy. The Ratio Calculator sits in that toolkit — it compare and simplify ratios, or solve for an unknown term in a ratio. 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.
Frequently asked questions
How useful was this calculator?
Your ratings stay in your browser — they help us learn which tools people actually rely on.