FindX - Proportion Solver

FindX - Proportion Solver finds the missing value in any proportion in seconds. Enter three numbers from a/b = c/d and get x right away. No sign-up, no account, and no internet needed to calculate.

WHAT IS A PROPORTION?
A proportion says two ratios are equal, for example 3/4 = x/12. Solving for x means using cross-multiplication, and FindX does that for you, so you can check homework, work faster, or skip the mental math.

WHY USE FINDX
- Solves a/b = c/d for any one unknown value
- Works fully offline: your calculations stay on your device
- No account, login, or personal data required
- Simple, clean calculator layout that is easy to use
- Light and dark theme options
- Optional keypress haptic feedback
- Lightweight and quick to open

GREAT FOR
- Students learning ratios, proportions, and cross-multiplication
- Homework checking in pre-algebra and algebra
- Parents and teachers who want a quick way to verify answers
- Scaling recipes and quantities
- Unit conversions and rate problems
- Map scales, model sizes, and percentage-style problems
- Anyone who needs a fast ratio calculator

HOW IT WORKS
1. Enter the three known values in the proportion a/b = c/d.
2. Leave the one you want to find as the unknown.
3. Tap solve to see the answer instantly.

EXAMPLES
- 2/5 = x/20 → find x
- If 3 notebooks cost 12, how much do 7 cost?
- A map scale of 1:50,000, and you want the real distance

PRIVACY FIRST
FindX does not collect or send the numbers you enter. Your inputs and theme preference are stored locally on your device. The app is supported by ads through Google AdMob, and you can manage ad personalization in your Android settings.

Whether you call it a proportion solver, ratio calculator, or cross-multiplication tool, FindX gives you the missing value fast.

Download FindX - Proportion Solver and solve proportions in seconds.