Free online calculators

Calculates press-fit pressure and stress for shaft and hub assemblies.

Shows how much a regular investment could grow to by retirement.

Finds resistor and capacitor values for a target cutoff frequency of RC filters.

Works out resistor values for series and parallel LED arrays from the supply voltage.

Gives the series resistor needed to drive an LED from a supply voltage.

UK income tax and take-home pay calculator for the 2026-27 tax year.

Picks the resistor pair or computes output voltage for an LM317 regulator.

Monthly repayments and interest for a loan or mortgage, with optional overpayments.

Index of ham radio calculators for antennas, attenuators, resonance and power units.

Estimates characteristic impedance of a PCB microstrip line from geometry.

Mortgage payment estimate with amortization schedule, payoff chart and extra-payment options.

Simulates long-term portfolio growth and retirement survival with random return paths.

Estimates the Canadian home price you can afford from income, debts and down payment.

Government of Canada tool to estimate mortgage payments and compare terms.

Mortgage payment including principal, interest, taxes and insurance, with an amortization table.

Mortgage payment estimate with PMI, property tax, insurance and HOA.

Canadian mortgage payment with amortization schedule across payment frequencies.

Converts American, decimal and fractional odds into each other and into implied probability.

Sizes a PCB trace for a given current, copper thickness and temperature rise.

Gives a rough idea of how much to save into a UK pension for the retirement income you want.

Forecasts income a UK pension could provide in retirement.

Estimates annual fuel costs and savings for vehicles based on how much and where you drive.

Checks whether current savings and contributions will cover retirement spending.

Visualizes the odds an early retiree's money outlasts them, factoring in longevity risk.