Math & Numbers
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.
power-transmission-efficiencyFinance
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.
present-value-calculatorMath & Numbers
Convert between pH, [H+], pOH and [OH-], or compute pH from a strong acid/base concentration, including dilution.
ph-calculatorMath & Numbers
Solve pressure, force, or area from P=F/A, and convert between Pa, kPa, MPa, bar, atm, psi, Torr, inHg, kgf/cm²
pressure-conversionMath & Numbers
Compute gravitational potential energy, mass, or height from the other two, with impact velocity
potential-energy-calculatorMath & Numbers
Compute range, max height, flight time, and the full trajectory of a projectile given speed, angle, and optional initial height
projectile-motion-calculatorMath & Numbers
Calculate buffer solution pH with the Henderson-Hasselbalch equation, or find the acid/base ratio needed for a target pH.
ph-buffer-calculatorMath & Numbers
Convert radians to degrees with configurable decimal precision
radians-to-degreesMath & Numbers
Convert pounds per square inch to bar with configurable decimal precision
psi-to-barMath & Numbers
Convert pounds per square inch to kilopascals with configurable decimal precision
psi-to-kpaMath & Numbers
Convert US liquid quarts to US liquid gallons with configurable decimal precision
quart-to-gallonMath & Numbers
Calculate coefficient of determination R squared from actual and predicted values
r-squared-calculator