What does the Ratio Calculator — Simplify & Solve do?

Divide an amount by a given ratio. Simplify ratios and see percentage splits. All calculations are performed in your browser using official UK rates and thresholds.

Is this calculator free to use?

Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.

Can I use this on my phone?

Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.

Ratio Calculator — Simplify & Solve

Divide an amount by a given ratio. Simplify ratios and see percentage splits.

Last updated: April 2026 · Source: BBC Bitesize — Ratios

Total Amount to Divide

Part A (3)

300

Part B (4)

400

Simplified ratio: 3 : 4

A is 42.9% · B is 57.1%

Disclaimer

This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.

How It Works

A ratio compares two or more quantities. This calculator simplifies ratios to their lowest terms, scales them up or down, and solves for an unknown value in a proportion. Enter values separated by colons (e.g. 12:8) to simplify, or enter three of four values in a proportion to find the missing one.

Ratios are used in cooking (scaling recipes), construction (mixing concrete at 1:2:3), finance (price-to-earnings ratios) and map reading (1:50,000 scale). The calculator shows the GCD used for simplification and the cross-multiplication step used for solving proportions.

Example: Simplify 45:60 and scale a recipe

GCD of 45 and 60 = 15
45:60 simplifies to 3:4
Recipe calls for 200 g flour at 3:4 ratio with sugar
Sugar needed: 200 × (4/3) = 266.67 g

Source: BBC Bitesize — Ratios

Frequently Asked Questions

What does the Ratio Calculator — Simplify & Solve do?: Divide an amount by a given ratio. Simplify ratios and see percentage splits. All calculations are performed in your browser using official UK rates and thresholds.
Is this calculator free to use?: Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.
Can I use this on my phone?: Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.