Free online calculators

Calculates impedance, resonance and phase of a series RLC circuit.

Computes pitch diameter and outside diameter of roller chain sprockets.

Finds reactions, shear, moment and deflection for a simply supported beam.

Mutual fund SIP projection from monthly investment, expected return and period.

Estimates Social Security retirement benefits and the effect of claiming age.

Finds the nearest standard E-series resistor values for a target resistance.

Fits Steinhart-Hart coefficients and converts thermistor resistance to temperature.

Estimates UK student loans, grants and bursaries you could get.

Calculates duty cycle, inductor ripple and currents for buck, boost and buck-boost converters.

Official US tool for checking how much federal tax your paycheck withholding covers and adjusting your W-4.

Quick estimate of a US tax refund or amount owed from income and deductions.

Relates PCB trace width, copper weight and temperature rise to current capacity.

Computes the reflection coefficient and reflected signal from an impedance mismatch.

Finds the output voltage of a two-resistor divider or the resistor needed for a target output.

Picks feedback resistors for an adjustable voltage regulator.

Computes element lengths and spacing for a three-element Yagi.

Computes straight-line 3D distance between two ECEF positions.

Reads a four-band resistor's value and tolerance from its colors.

Projects a 401(k) balance using salary, employer match and tax effects.

Decodes five-band precision resistors into value and tolerance.

Computes component values for a 555 astable oscillator at a chosen frequency and duty cycle.

Computes frequency, duty cycle and pulse width for 555 astable and monostable setups.

Finds the pulse width of a 555 one-shot from its resistor and capacitor.

Converts between 5G NR ARFCN numbers and carrier frequency.