# Ratio Calculator

Simplify ratios, convert to percentages, and scale to any total. Supports two-part and three-part ratios. Free online ratio calculator with instant.

## What this calculates

Simplify any ratio to its lowest terms, convert to percentages, and scale to a specific total. This free calculator supports both two-part and three-part ratios for cooking, mixing, construction, and more.

## Inputs

- **Part A** — The first part of the ratio.
- **Part B** — The second part of the ratio.
- **Part C (optional)** — Optional third part for a three-part ratio.
- **Scale Total To** — Scale the ratio so parts add up to this total.

## Outputs

- **Simplified Ratio** — formatted as text — The ratio reduced to its simplest form.
- **Decimal Ratio** — formatted as text — Each part expressed as a decimal relative to the first part.
- **Percentages** — formatted as text — Each part as a percentage of the total.
- **Scaled Values** — formatted as text — Parts scaled to the specified total.

## Details

A ratio expresses the relative sizes of two or more values. Ratios are used everywhere: recipes (flour to water), map scales, financial analysis, mixing solutions, and architectural proportions.

Simplifying Ratios

To simplify a ratio, divide all parts by their greatest common divisor (GCD). For example, 12:8 simplifies to 3:2 because GCD(12, 8) = 4.

Scaling Ratios

To scale a ratio to a specific total, divide the total by the sum of the ratio parts, then multiply each part by that factor. For a 3:2 ratio scaled to 100: each unit = 100/5 = 20, so the parts are 60:40.

Ratios differ from fractions in that they compare parts to parts, while fractions compare a part to the whole. However, ratios and fractions are closely related and often interconvertible.

## Frequently Asked Questions

**Q: How do I simplify a ratio?**

A: Find the greatest common divisor (GCD) of all parts and divide each part by it. For example, the ratio 24:36 has a GCD of 12, so it simplifies to 2:3. If the ratio contains decimals, first multiply all parts by a power of 10 to eliminate them, then simplify.

**Q: What is the difference between a ratio and a fraction?**

A: A ratio compares two or more quantities to each other (part to part), like 3:2. A fraction compares a part to the whole, like 3/5. The ratio 3:2 means for every 3 of one thing, there are 2 of another. As fractions of the total, these would be 3/5 and 2/5.

**Q: How do I convert a ratio to percentages?**

A: Add all parts together to get the total, then divide each part by the total and multiply by 100. For the ratio 3:2:5, the total is 10, so the percentages are 30%, 20%, and 50%. This is useful for understanding the proportional distribution.

**Q: Can ratios have decimals or fractions?**

A: Yes, ratios can contain decimals or fractions. The ratio 1.5:2.5 is valid and simplifies to 3:5 (multiply both by 2). Similarly, 1/3:1/2 can be converted by finding a common denominator, yielding 2:3.

**Q: How are ratios used in real life?**

A: Ratios are used constantly in cooking (ingredient proportions), construction (concrete mix ratios like 1:2:3 for cement, sand, gravel), finance (price-to-earnings ratios), science (chemical solution concentrations), and map reading (scale factors). Understanding ratios helps you scale recipes, mix materials correctly, and interpret data.

---

Source: https://vastcalc.com/calculators/math/ratio
Category: Math
Last updated: 2026-04-21