Free online calculators

Shows how much invested now would let compounding reach retirement without more saving.

Gives wavelength in coaxial cable from frequency and velocity factor.

Estimates the inductance of a wound coil from turns, diameter and length.

Checks compression members for buckling with Euler, Johnson and secant methods.

Computes Euler buckling load of a column for different end supports.

Designs a compression spring for a target load and checks stress.

Gives minimum conductor spacing on a PCB for a working voltage.

Gives counterbore diameter and depth for socket head cap screws.

Computes CRC-8, CRC-16 and CRC-32 checksums across many algorithm variants.

Computes volume, surface area and related properties of a cylinder.

Estimates battery life for a device that wakes periodically to sample and sleeps between.

Calculates days between dates and adds or subtracts time from a date.

Converts between decibels and power or voltage ratios.

Converts between decibels, power ratios and voltage ratios.

Basic calculator for add, subtract, multiply and divide with a simple keypad.

Scientific calculator with trig, logs, statistics and a recallable expression history.

Compares LLM request and monthly costs across providers from input, output and cached token counts.

Years to financial independence from income, expenses and savings rate.

Monthly EMI for home, car and personal loans with interest breakup.

Monthly instalment and total interest for a home, car or personal loan.

EMI calculator for home, car and personal loans in India with a repayment schedule.

Projects Employee Provident Fund contributions and corpus.

Converts transmitter power, feed loss and antenna gain into ERP and EIRP.

Official HMRC estimate of income tax for the current tax year.