Calculate the overall efficiency of a multi-stage transmission. η_total = η₁·η₂·…·ηₙ. Enter one stage efficiency per line (decimal, e.g. 0.98). Optionally add an input power to get the total loss and per-stage output power.

Finance

Present Value Calculator

Discount a future lump sum or an annuity back to today's value (PV). Supports lump-sum and annuity cash flows, multiple compounding frequencies, a present-value decay curve, and a per-period breakdown. PV = FV / (1+r)^n for a lump sum.

Math & Numbers

pH Calculator

Convert between pH, [H+], pOH and [OH-], or compute pH from a strong acid/base concentration, including dilution.

Math & Numbers

Pressure Calculator & Converter (P=F/A, Pa/kPa/bar/atm/psi)

Solve pressure, force, or area from P=F/A, and convert between Pa, kPa, MPa, bar, atm, psi, Torr, inHg, kgf/cm²

Math & Numbers

Potential Energy Calculator (PE = mgh)

Compute gravitational potential energy, mass, or height from the other two, with impact velocity

Math & Numbers

Projectile Motion Calculator (Range, Height, Time)

Compute range, max height, flight time, and the full trajectory of a projectile given speed, angle, and optional initial height

Math & Numbers

pH & Buffer Calculator

Calculate buffer solution pH with the Henderson-Hasselbalch equation, or find the acid/base ratio needed for a target pH.

Math & Numbers

Radians to Degrees

Convert radians to degrees with configurable decimal precision

Math & Numbers

PSI to Bar

Convert pounds per square inch to bar with configurable decimal precision

Math & Numbers

PSI to KPa

Convert pounds per square inch to kilopascals with configurable decimal precision

Math & Numbers

Quart to Gallon

Convert US liquid quarts to US liquid gallons with configurable decimal precision

Math & Numbers

R-Squared Calculator

Calculate coefficient of determination R squared from actual and predicted values