๐ซ Electric Kettle Boil Time Calculator
If you don't know the efficiency, around 90% is a reasonable estimate.
Enter the volume of water (mL), starting and target temperature, and your electric kettle's wattage to estimate how long it will take to heat, based on the specific heat of water (4.186 J/gยฐC).
How to use
- Enter the volume of water to boil (mL).
- Enter the kettle's power consumption (W).
- Enter the starting and target temperature (usually 100ยฐC).
- Enter the heating efficiency (%) โ around 90% is a reasonable default if unknown.
FAQ
What formula does this use?
It uses the basic physics formula Q (joules) = mass (g) ร specific heat of water (4.186 J/gยฐC) ร temperature change (ยฐC), then divides by the effective wattage (power ร efficiency) to get time.
Why does efficiency matter?
In a real kettle, some power is lost to heating the container and the surrounding air rather than the water itself, so the actual time is longer than the theoretical value. The efficiency factor corrects for this.
Does this assume water is 1g per mL?
Yes โ water near room temperature is close enough to 1mL = 1g for this calculation.