Calculators & Converters

Ratio Calculator

Turn two nonnegative amounts into their simplest whole-number ratio, then split a total using the same proportions. Decimal ratio parts are supported, and the two exact shares always add back to the entered total.

Free online tool

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Reduce a ratio and divide a total

Positive decimals work too: 1.5:1 reduces to 3:2. The total must use the same units for both shares.

Results

Simplest whole-number ratio
3:2
First share
150
Second share
100

First share = total × first part ÷ sum of parts. Rounded visual percentages do not affect the exact calculations.

Exact shares: 150 and 100

First part for every one second part
1.5

Calculations and exports run locally in your browser. Your entries are not sent to a calculation service.

GET STARTED

How to use the Ratio Calculator

  1. 01

    Enter the first and second ratio parts in matching units. At least one part must be positive.

  2. 02

    Enter the total quantity you want to distribute between the two parts.

  3. 03

    Read the reduced ratio, the two shares, and the first-to-second unit rate. Copy or download the allocation.

Examples

Divide a supply

A 3:2 allocation of 250 sheets gives 150 sheets to the first group and 100 sheets to the second.

Simplify decimal parts

A ratio of 1.5 to 1 has the same proportions as 3:2. Clearing decimal denominators before finding the greatest common divisor makes this reduction exact.

Keep zero as a real part

A 0:4 ratio reduces to 0:1. Splitting 60 units gives zero to the first part and all 60 to the second.

Ratio parts are relative weights

A 3:2 ratio contains five parts in total. The first share is total × 3 ÷ 5, and the second is total × 2 ÷ 5. The ratio does not imply there are only five objects; any common scale preserves it.

Part-to-part differs from part-to-whole

The ratio 3:2 describes the first share compared with the second. The first share is 3/5, or 60%, of the combined total. Confusing 3/2 with 3/5 produces a different result, so the calculator labels both shares explicitly.

Discrete quantities need an allocation rule

The exact split can contain fractions. A 2:1 split of ten tickets gives 20/3 and 10/3, which cannot be allocated as literal whole tickets. This tool leaves the shares exact rather than choosing who receives a rounding remainder.

What to know

  • Two ratio parts only; whole-object remainders are not allocated.
  • Decimal displays truncate after 12 places, while exact fractional shares are retained.

Common questions

Can both parts be zero?

No. A zero-to-zero ratio has no defined proportion. A single zero part is valid and receives none of the total.

Can I use a negative ratio?

This workflow is for nonnegative allocation weights and rejects negative parts or totals. Signed algebraic ratios need a different interpretation.

Can I simplify a ratio without splitting anything?

Yes. Leave the total at its example value and read the reduced ratio. Changing the total never changes the reduced ratio.

Sources & references