Calculator
What the Ratio Calculator does
Ratio Calculator: calculates Simplified A/B and A ÷ B from Part A and Part B. Example: part a 2 and part b 3 gives simplified A/B 2/3.
Simplified A/B and A ÷ B, derived from Part A and Part B. Edit a field and the answer updates in place.
Typical users are students checking homework. A second opinion on a calculation takes seconds and prevents errors compounding.
There is no back end here. The calculation runs where you are sitting, not on a server somewhere.
If you want to check the arithmetic, the field table, the method and a worked example are further down.
What do the Ratio Calculator fields mean?
The Ratio Calculator uses 2 inputs. You can work from the defaults, or clear them and start fresh, both work.
| Field | What to enter | Default |
|---|---|---|
| Part A | required | 2 |
| Part B | required | 3 |
How does the Ratio Calculator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same calculation.
Validation is deliberately strict: silently coercing a bad value is how wrong numbers get trusted.
Worked example
These are the values the Ratio Calculator loads by default, and the result it produces from them. Here is the calculation as it stands the moment the page loads.
| Part A | 2 |
|---|---|
| Part B | 3 |
| Simplified A/B | 2/3 |
|---|---|
| A ÷ B | 0.666667 |
| What this means | Ratio A:B simplifies to 2:3 |
Beyond the formula: simplifying ratios
A ratio like 2:3 describes a relationship between quantities, not the quantities themselves: 2:3 and 200:300 represent the identical relationship, which is exactly what simplifying (dividing both sides by their GCD) reveals.
Common mistakes and sanity checks
- A ratio is not the same as a fraction of the whole: in a 2:3 ratio of two parts, the first part is 2/5 of the total, not 2/3. The denominator for "share of total" is the sum of the ratio terms, a step people frequently skip.
- Ratios with more than two terms (mixing concrete at 1:2:3 cement:sand:gravel, say) simplify the same way, by dividing every term by the GCD of all of them, though this calculator handles the two-term case.
- Order matters: a 3:2 ratio is the inverse relationship of 2:3, not the same ratio written differently, always confirm which quantity comes first when comparing ratios pulled from different sources.
How to use it
- Fill in Part A.
- Type Part B.
- Type a value and the answer is already there by the time you stop.
- The panel reports Simplified A/B, A ÷ B and What this means.
- Copy Link is the quickest way to send the exact scenario to someone else.
What this tool does not do
- Displayed values are rounded; the underlying calculation keeps full precision.
- Very large or very small values reach the limits of floating-point precision, about 15 significant digits.
- Nothing is saved between visits, so keep your own record of anything you need again.
Frequently asked questions
Only Part A and Part B. Nothing starts empty, meaning you can explore the calculation before committing to real figures.
With the values loaded when the page opens, simplified A/B comes out as 2/3. Any edit re-runs the calculation, so there is no stale number on screen.
No: there is no server involved. Close the tab and the values are gone.
Nothing at all. There is no registration, no paywall and no per-use quota.
It matches what you would get working it out by hand, with fewer opportunities to slip.