A growing collection of free calculators for money, maths, engineering and everyday life. Fast, accurate and easy to use.
Work out monthly payments, total interest and total repayment.
Open Calculator →Calculate your net salary after tax, NI, pension and student loans.
Open Calculator →Work out how much tax you pay on dividends based on your income band.
Open Calculator →Calculate SDLT for first‑time buyers, home movers and second homes.
Open Calculator →Increase, decrease, discounts, original price, percentage of, percentage change and more.
Open Calculator →Convert 4–20 mA or 0–10 V signals to engineering units and back.
Open Calculator →Convert length, mass, temperature, pressure, volume, speed, energy, power and more.
Open Converter →Work out volts, amps, resistance and power from any two known values.
Open Calculator →Calculate power, voltage, current and power factor for AC and DC circuits.
Open Calculator →Convert between frequency and wavelength for sound and EM waves.
Open Calculator →Use Howard’s AI Prompt Starter Pack to generate financial summaries, explanations, emails and more — instantly.
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