Over 1,300 engineering calculators in one place — hydraulics, heating, ventilation, mechanics, geometry, and more. Free, no sign-up, no install. Just a browser.
A growing library of single-purpose calculators, each built around one formula or one engineering question. No spreadsheets, no plugins — just open the page, type values, get a result.
Reynolds number, pressure drop, NPSH, pipe sizing, flow regimes — 337 calculators across hydraulics, ventilation, and HVAC.
Heat transfer, U-values, psychrometrics, combustion — 206 thermodynamics calculators plus 266 heating-industry tools.
Beam equations, stress and strain, shaft sizing, bolted joints — 184 mechanics + 165 statics calculators.
Areas, volumes, regression (MNK), unit conversions — 125 geometry + 97 math calculators with clean inputs.
Battery sizing, cable cross-sections, plus chemistry, materials science, acoustics — 200+ calculators across the rest of physics.
Built-in i18n for Polish, English, German, French, Spanish, and more. Numbers and units adapt to locale.
| Physics | 554 |
|---|---|
| Fluid mechanics | 337 |
| District heating & HVAC | 266 / 73 / 29 |
| Thermodynamics | 206 |
| Hydraulics | 207 |
| Construction | 189 |
| Mechanics & statics | 184 / 165 |
| Geometry & math | 125 / 97 |
| Chemistry | 98 |
| Materials science | 47 |
| Electrical | 33 |
| Acoustics, numerics, OZE, 3D printing, ... | 50+ |
Counts as of last database export. Each calculator may belong to multiple categories.
| Stack | Vanilla HTML, CSS, JavaScript (ES6+, Web Components) |
|---|---|
| Formulas | mathjs (declarative defineCalculator runtime) |
| Languages | 12 (i18n built-in) |
| Build step | None — pages load instantly, no framework. |
| Price | Free, forever. Donations optional. |
No sign-up, no install, no payment. Bookmark kalkulator.modeltok.com and you're done.