Ratio calculator (share an amount in a ratio)
Type the ratio and the total to share, and this calculator does the standard GCSE method for you: add the parts, divide to find one part, then multiply. It also simplifies the ratio, shows each share as a fraction of the total, and works with two, three or four parts.
Share an amount in a ratio
90 : 150
Ratio: 3 : 5 (simplified 3 : 5, 8 parts)
One part: 30
Each share
- Part 1 (3) → 90 — that is 3/8 of the total
- Part 2 (5) → 150 — that is 5/8 of the total
Working
- Total parts = 3 + 5 = 8
- One part = 240 ÷ 8 = 30
- Share 1 = 30 × 3 = 90
- Share 2 = 30 × 5 = 150
The method behind it
- Total parts = sum of the ratio parts.
- One part = amount ÷ total parts.
- Each share = one part × that ratio number; each fraction = part ÷ total parts.
How to use this tool
1. Enter the ratio parts
Type each part of the ratio into its own box, for example 3, 5 and 7 for 3:5:7. Leave a box blank if your ratio has fewer parts.
2. Enter the amount to share
Put the total quantity being divided — money, mass, time or anything else — into the total box.
3. Read the working
Check the number of parts, the value of one part, and each share. The fractions of the total are useful when a question asks for the answer as a fraction rather than an amount.
Frequently asked questions
How do you share an amount in a ratio?
Add the ratio parts to get the total number of parts, divide the amount by that total to find the value of one part, then multiply that value by each part of the ratio. For example, £120 in 3:5 gives 8 parts, one part = £15, so the shares are £45 and £75.
How do you simplify a ratio?
Divide every part by their highest common factor. For example, 12:18:30 all divide by 6, giving 2:3:5. A simplified ratio has no common factor other than 1.
How do you write a ratio as a fraction of the total?
Each part becomes the numerator and the total number of parts becomes the denominator. In 3:5, the first share is 3/8 of the total and the second is 5/8.
Can this calculator handle three-part ratios?
Yes — it accepts up to four parts, which covers every GCSE and IGCSE ratio question, including recipe scaling and money-sharing problems.
Practise this properly, not just once
A solver gives you the answer; exam marks come from the working. MathsGradeUp pairs exam-board questions with step-by-step feedback and revision notes on the exact topics you keep dropping marks on.