A small tool that does one job well
www.lcm-calculator.com started as a homework helper — a place to check LCM answers without wading through ads, newsletters, or “download our app†banners. The calculator runs entirely in the browser, shows its work via prime factors, and pairs with a GCD tool because those two ideas are inseparable.
We keep the pages short on purpose. Math sites from the mid-2010s that still help people tend to share that habit: clear inputs, readable steps, no fluff.
What's on the site
- LCM calculator for 2–6 integers
- GCD / HCF calculator
- Prime factorization
- Explainers: how it works, formulas, examples, FAQ
For teachers
You're welcome to project the calculator in class or link it from a course page. If a worked example on your worksheet disagrees with the tool, check whether zero, negatives, or decimals sneaked in — those are the usual culprits.