Tools
Appliance running cost calculator UK: heaters, blankets
Work out what a heater, dehumidifier, electric blanket or air fryer costs to run in the UK at the October 2026 price cap, per hour, day, week and month, with the working shown.
Tools
Small calculators and converters that run in your browser. Use them here or copy the code.
Electronics
Light the Lamp: a logic gate puzzle game
A free logic gate puzzle game with 153 levels: flick the switches to light the lamp, starting with one wire and working up through NOT, AND, OR, NAND, NOR and XOR gates to number displays, adders and memory, then 50 levels from hard to extreme.
Tools
Electric car cost calculator UK: by number plate, with the 3p-a-mile charge
Type your number plate: the calculator reads your yearly mileage from your car's MOT history and shows what an electric car would cost you, at home or public chargers, with the 3p-a-mile charge from April 2028. It also shows how long one charge takes and what it costs.
Tools
MOT history check: advisories explained in plain English
Check any car's MOT history by number plate, with each advisory explained in plain English, the mileage readings checked, repeated faults picked out, and questions to ask a seller.
Tools
EV charging subscriptions: which one saves you money?
Type how much you charge at rapid chargers each month and see whether an IONITY, Tesla, bp pulse, GRIDSERVE, Shell, Fastned or Be.EV subscription would save you money, with each network's prices checked in October 2026.
Electronics
Capacitor code calculator: what 104, 473 and 2A104J mean
Type the code printed on a capacitor, such as 104, 473J or 2A104J, and get the value in pF, nF and µF with the tolerance and voltage. Works both ways.
Tools
Controller tester: test your gamepad for stick drift
A free controller tester that runs in your browser: check every button, trigger and stick on a PlayStation, Xbox, Switch or PC controller, and test the sticks for drift.
Electronics
LED resistor calculator: what resistor for 12 V?
Work out the series resistor for an LED on 12 V, 5 V or any supply. Rounds up to a standard value and shows the current and the resistor's power.
3D Printing
3D print cost calculator: what prints really cost in the UK
A free calculator for the real cost of a 3D print in the UK, with filament prices, printer power figures and the maths shown.
Tools
How to write formulas on this site
Write maths in plain words and symbols and the site typesets it. Every example on this page, with what you type and what the reader sees.