Tool City

Free tools for everyone, everything, everywhere

Math & Numbers

Ratio simplify & solve

Ratio Calculator - free online ratio calculator tool with instant results. Use it for arithmetic, percentage, finance, and numeric problem solving.

No data stored Instant results Mobile-first 100% Free

Mode & values

Use positive numbers only. For “solve”, fill either C or D — not both.

Guide, FAQs & related tools

What Is a Ratio Calculator?

A ratio calculator either reduces a pair of positive numbers to the smallest equivalent integer ratio, or solves for a missing value in a proportion where A:B equals C:D (enter either C or D, not both).

Mixing paint, scaling recipes, maps, screen layouts and exam problems all use ratios and proportions.

How to Use the Ratio Calculator - Step by Step

  1. 1

    Pick mode

    Simplify or solve proportion.

  2. 2

    Enter values

    Positive numbers only; follow on-screen hints for solve mode.

  3. 3

    Calculate

    Get simplified integers or the missing term.

Frequently Asked Questions - Ratio Calculator

Guide & insights

Ratio Calculator — complete guide

Clear explanations, practical tips and how this free ratio calculator fits real workflows — optimized for reading on any device.

What is the Ratio Calculator?

A ratio calculator either reduces a pair of positive numbers to the smallest equivalent integer ratio, or solves for a missing value in a proportion where A:B equals C:D (enter either C or D, not both).

Why people use this calculator

Mixing paint, scaling recipes, maps, screen layouts and exam problems all use ratios and proportions.

How to use the Ratio Calculator — summary

  • Pick mode: Simplify or solve proportion.
  • Enter values: Positive numbers only; follow on-screen hints for solve mode.
  • Calculate: Get simplified integers or the missing term.

Tips for best results

Double-check classroom or exam problems with a second method when precision matters. Cross-check loan or investment figures with your bank’s official schedule — small rounding differences are normal between calculators.