How do I simplify a ratio?

Divide both sides by their greatest common divisor: 18:24 has GCD 6, simplifying to 3:4. The calculator shows the GCD used and handles decimal ratios by clearing decimals first.

How do I solve a proportion with a missing value?

Cross-multiply: if 3:4 = 9:x, then 3x = 36, so x = 12. Enter three values and the calculator finds the fourth, whichever position is unknown.

How do I scale a ratio to a new total?

A 2:3 ratio splitting $400 means 5 parts of $80 each → $160:$240. The calculator distributes any total across ratio parts — the mechanics behind recipe scaling, aspect ratios, and profit sharing.

How do ratios convert to fractions and percentages?

A ratio 3:4 means parts of a 7-part whole: 3/7 ≈ 42.9% and 4/7 ≈ 57.1%. The calculator shows fraction and percentage views alongside every result.

Can it handle three-part ratios?

Yes — simplify, scale, and distribute totals across ratios like 2:3:5 (e.g., splitting an investment three ways).

Ratio Calculator — Simplify, Scale & Solve Ratios, Free...

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Ratio Calculator — Simplify, Solve, Scale

Ratios run the practical world: recipe proportions, screen dimensions, map scales, paint mixes, profit splits. This free calculator simplifies any ratio to lowest terms, solves proportions for missing values by cross-multiplication, distributes totals across ratio parts, and converts to fractions and percentages — with every step shown. In-browser, no signup.

The Four Operations

Task	Example	Answer
Simplify	18:24	3:4 (÷ GCD 6)
Solve proportion	3:4 = 9:x	x = 12 (cross-multiply)
Distribute a total	2:3 over $400	$160 : $240
Convert	3:4 as %	42.9% : 57.1% (of 7 parts)

Cross-Multiplication: The One Move to Master

Equal ratios have equal cross-products: a:b = c:d exactly when a·d = b·c. Every proportion problem — currency at a known rate, ingredient scaling, similar triangles, price per unit — reduces to this one multiplication and one division. The calculator displays the cross-product step so the method transfers to exam problems done by hand.

Everyday Ratio Problems, Solved

Cooking — rice to water 1:1.5 for 400 g rice → 600 ml water; scale whole recipes by solving each ingredient's proportion.
Screens and images — 16:9 at 1280 wide → height 720; resizing without distortion is proportion-solving (our aspect ratio calculator specializes here).
Finance — partners at 2:3:5 splitting $50,000 profit receive $10k/$15k/$25k; the three-part distributor does it in one step.
Maps and models — 1:50,000 scale means 4 cm on paper = 2 km of terrain.
Mixing — fuel at 50:1, fertilizer at 20:1, mortar at 1:3 — enter the ratio and your total volume, get exact quantities.

Free and Instant

All operations with worked steps, computed locally — from homework to job sites to kitchens.

Ratio Calculator

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