Home Improvement Toolkit

Calculate square footage online free for rooms, floors and yards in feet, inches, meters or yards. Free online square feet calculator with waste and cost.

Calculate the volume of a cube, box, cylinder, sphere, cone, pyramid and more with this free online volume calculator — in litres, gallons, m³ and ft³.

Measure with an actual-size online ruler in cm, mm and inches — calibrate with a bank card or your screen size for real accuracy. Free online ruler.

Convert units online free: cm to inches, kg to lbs, °C to °F, ml to oz, mph to km/h, MB to GB and more. Free online unit converter with exact factors.

Calculate how much paint you need for a room with this free online paint calculator: walls, ceiling, doors, windows and coats, in gallons or liters.

Calculate how much concrete you need for a slab, footing or column with this free online concrete calculator, in cubic yards or m³ plus 80, 60 or 40 lb bags.

Calculate how much gravel, stone, sand, topsoil or mulch you need with this free online gravel calculator, in cubic yards, tons, m³ or bags.

Calculate what an appliance costs to run per day, month and year with this free online electricity cost calculator from its watts, hours and price per kWh.

Calculate voltage, current, resistance and power with this free online Ohm's law calculator — enter any two values and get the other two in mA, kΩ or kW.

Find the ideal TV size for your room or the best viewing distance for a screen you own. Free online TV size calculator with SMPTE, THX and 4K/8K presets.