QuickEngCalc is a suite of browser calculators for electrical, statistics and mechanical work. Electrical tools include voltage drop and wire sizing, watts to amps, amps to watts and motor HP to amps. Statistics tools include z-score, percentile and p-value. Mechanical tools include lbf to newton, gear ratio, bend allowance and sheet metal K-factor. There is also a CFD y+ estimator, a Karnaugh map solver and a microwave wattage converter.
Each calculator shows its formula, a worked example and reference tables. The site says all calculators are free with no sign-up, no stated usage limit and no paid tiers, and that calculations run locally in the browser. It works on phone, tablet and desktop. Results are estimates and not for safety-critical use.
QuickEngCalc was built to offer free engineering calculators with transparent formulas and worked examples, without a signup.