Ratio Calculator
Enter any two positive numbers to reduce the ratio to its simplest form, then scale it: give a new value for the first term and the calculator finds the matching second term. Ratios appear in Class 6 maths, in recipes, and on every preschool's teacher-child ratio.
Enter two positive numbers - the ratio is reduced to its lowest terms instantly.
Scale the ratio
Keep the same ratio but change the first term - the calculator finds the matching second term. e.g. a 2:3 dosa batter recipe scaled up for guests.
Parents also ask
How do I simplify a ratio?
Divide both terms by their highest common factor (HCF). For 12:18 the HCF is 6, so the simplest form is 2:3. This calculator finds the HCF for you and handles decimals too.
When do children learn ratios in India?
Ratio and proportion formally start in Class 6 across most boards, but the idea shows up earlier through sharing and recipes - '2 cups rice to 3 cups water' is a ratio a child can cook with.
What is a good teacher-child ratio at a preschool?
For playgroup and nursery, look for around 1:10 or better (some premium centres offer 1:8), and up to 1:15 for UKG. Ask how many adults are actually in the room, including helpers - that is the ratio that matters on a normal day.
How do I scale a ratio?
Multiply or divide both terms by the same number. If a recipe uses milk and water in the ratio 2:3 and you take 6 cups of milk, you have multiplied by 3, so you need 9 cups of water. The scale section below does this automatically.