About Proportion Calculator
A simple site for solving proportion and ratio problems, with every step shown
Who we are
Proportion Calculator is an independent website built around one goal: making proportion and ratio problems easier to solve. Jason Miller created and maintains the site, with a focus on keeping the tool accurate, fast, and free to use.
This isn’t a large company or a team of dozens of contributors. It’s a straightforward project run by someone who understands that a simple math problem shouldn’t require a complicated tool to solve it.
What Proportion Calculator Does
The calculator solves for a missing value in any proportion. Enter three known numbers, and it returns the fourth, along with the steps used to reach that answer. Behind the scenes, it applies cross multiplication, the same method taught in classrooms and used in professional settings, so the result matches what you’d get solving it by hand.
Beyond the calculator itself, this site includes explanations of how proportions work, worked examples, and guidance on solving proportions manually. The goal isn’t just to hand you an answer. It’s to help you understand how that answer was reached, so you can apply the same logic to your own problems later.
Who Uses Our Tool
People come to this site for different reasons.
Student
Check homework or study for exams and more
Teachers
Prepare lesson examples or verify answer keys.
Architects
work through measurement conversions.
Researchers
Run quick calculations involving rates, ratios.
Brockers
calculating proportional relationships for fees
Everyday
Scale drawings or work through measurement conversions.
The site is built to run smoothly on both desktop and mobile devices, so it’s available whether you’re at a desk or checking something on your phone
Why we created Proportion Calculator
Proportion problems come up constantly, in classrooms, at work, and in daily life, but most calculators either bury the math behind a confusing interface or just hand over a number with no explanation. This site was built to fix that: a calculator that’s quick to use and shows its work, paired with content that actually explains the concept instead of assuming you already know it.
This isn’t a large company or a team of dozens of contributors. It’s a straightforward project run by someone who understands that a simple math problem shouldn’t require a complicated tool to solve it.
Get in touch.
If you have questions, feedback, or run into something that doesn’t look right, you can reach out at contact@proportioncalc.us. You can also find the calculator and related content at https://proportioncalc.us.
Got a proportion to solve?
Get the awnser and every steps in seconds