Convert and calculate, free
BTU for your AC, mm to cm, pool chlorine dose, paint liters and more — plus unit conversions and image tools (resize, favicon, translate lecture slides). All in your browser, no signup.
What size air conditioner do I need (BTU calculator)
m² → BTU
Air conditioner and appliance electricity cost calculator
kWh · bill
Pool chlorine calculator — how much chlorine (g & tablets)
m³ → grams
Cocktail calculator — doses for any party size
guests → ml
Party shopping list — how much per guest
guests → shopping list
Portable cooler size — liters for people and days
ice · hours → L