About Calcora

Calcora is a free collection of fast, accurate online calculators for everyday life: money, health, home projects, math, and unit conversions. No signup, no app, no paywall. Every calculator runs entirely in your browser, so your numbers never leave your device.

Who runs Calcora

Calcora is built and operated by RKServicesPDX. It is maintained as a single, coherent catalog rather than a loose pile of one-off tools: every calculator, guide, and category shares one data source, so the numbers you see, the sitemap, and the machine-readable catalog can never drift apart.

How the calculators are built

Each calculator is written from its underlying formula, not scraped or guessed. Wherever it helps, a calculator page also shows how it works, the formula it uses, and worked examples, so you can check the result yourself instead of trusting a black box. Home-project estimators pair with step-by-step DIY guides, and conversions use standard, published unit factors.

We favor plain, verifiable math over hidden assumptions. Where an estimate depends on real-world variables — waste factors on material estimators, rounding on conversions — the calculator says so rather than implying false precision. Home-improvement estimates are planning aids, not a substitute for professional measurement.

Always growing

We are always adding more calculators. If one you need is missing, the contact page is the place to ask; requests genuinely drive what we build next.

Calcora is operated by RKServicesPDX.