Calculations.one
Cooking • Finance • School • Design

Ratio Calculator

One tool, 5 calculators: simplify a ratio, convert it to a fraction, percentage, or decimal, solve a proportion, split an amount by ratio, and compare two ratios to see which is larger.

5
Calculators in One
Instant
Live Results
100%
Free & Accurate

Why Use This Ratio Calculator?

  • ✓ Covers every common ratio problem in one place.
  • ✓ Splits any amount into parts by ratio — great for recipes, budgets, and mixes.
  • ✓ Visual ratio bar shows each part's proportional share at a glance.

On This Page

Ratio Calculator Quick Reference Table Ratio Formulas Worked Examples Best Practices FAQs Related Calculators

Ratio Calculator

Simplify a ratio A : B

Use this to reduce any ratio to its simplest whole-number form.

Simplified Ratio
2 : 3

Enter both values to begin.

Convert a ratio A : B

Use this to express a ratio as a fraction, decimal, or as each part's percentage share of the total.

Fraction (A/B)
3/4
Decimal (A ÷ B)
0.75
Share of Total
A = 42.86%   B = 57.14%

Solve A : B = C : ?

:
=
:

Use this to find the missing 4th value in a proportion using cross multiplication.

Missing Value
20

Enter A, B, and C to begin.

Split a total amount by ratio

Use this to split a bill, budget, recipe batch, or profit share among any number of parts.

Split Result

Enter a total and ratio to begin.

Compare two ratios

Use this to check if two ratios are equivalent, or to see which one is larger.

Comparison
Equivalent

Enter both ratios to begin.

Common Ratio-to-Percentage Reference

Ratio Simplified Part A % Part B %

Ratio Formulas

Simplify a Ratio

A : B = (A ÷ GCD) : (B ÷ GCD)

Ratio to Percentage

A% = A ÷ (A + B) × 100

Solving a Proportion

A : B = C : D  →  D = (B × C) ÷ A

Splitting a Total

Part = (Part's Ratio Value ÷ Sum of Ratio Values) × Total

Comparing Ratios

A₁ : B₁ vs A₂ : B₂ are equivalent when A₁ × B₂ = A₂ × B₁

Worked Examples

Example 1 — Simplify 24:36

GCD(24, 36) = 12 → 24÷12 : 36÷12 = 2 : 3

Example 2 — Solve 2:5 = 8:?

? = (5 × 8) ÷ 2 = 20

Example 3 — Split $1,000 in the ratio 2:3:5

Total shares = 10 → Part 1 = $200, Part 2 = $300, Part 3 = $500

Example 4 — Compare 3:4 and 6:8

3 × 8 = 24, and 4 × 6 = 24 → the ratios are equivalent

Where Ratios Are Used

🍳 Cooking & Recipes

Scale ingredient ratios up or down while keeping the same flavor balance.

💰 Finance & Business

Split profits, expenses, or investments among partners based on agreed shares.

🎨 Design & Photography

Maintain consistent aspect ratios when resizing images, layouts, or prints.

🧪 Science & Mixing

Prepare solutions, concrete mixes, or fertilizers to an exact concentration ratio.

🎓 School & Homework

Solve ratio and proportion word problems in math class.

📊 Maps & Scale Models

Convert map or model scale ratios into real-world distances and sizes.

Best Practices & Common Mistakes

✅ Best Practices

  • Always simplify a ratio to its lowest terms for clarity.
  • Keep the order of terms consistent (A:B is not the same as B:A).
  • Use cross multiplication to solve any missing value in a proportion.
  • Add all ratio parts together first when splitting a total amount.
  • Convert to decimals when comparing more than two ratios at once.

❌ Common Mistakes

  • Reversing the order of terms in a ratio or proportion.
  • Adding ratio terms directly instead of using their proportional shares.
  • Forgetting to simplify before comparing two ratios.
  • Mixing units (e.g. minutes and hours) within the same ratio.
  • Assuming a larger first term always means a larger ratio.

Frequently Asked Questions

Divide both terms of the ratio by their greatest common divisor (GCD) until no common factor remains. For example, 24:36 simplifies to 2:3.
Use cross multiplication: for A:B = C:D, multiply A by D and B by C, then solve the resulting equation for the unknown value.
Add all the parts of the ratio together to find the total number of shares, then multiply the total amount by each part's share of that total.
Cross multiply the two ratios. If the two products are equal, the ratios are equivalent — for example, 3:4 and 6:8 are equivalent because 3×8 = 4×6 = 24.
A ratio compares two separate quantities (like 3 boys to 4 girls), while a fraction usually represents a part of a single whole. Ratios can still be written and simplified like fractions.
Yes. Ratios can compare three or more quantities at once, such as 2:3:5, which is common when splitting an amount into several parts.
Yes. All five calculators use standard ratio and proportion formulas and calculate results instantly with full decimal precision.

Need More Math Tools?

Explore hundreds of free online calculators for math, finance, health, construction, education, and everyday calculations.

Browse Math Calculators All Calculators