How long does a kettle take to boil?

2:56

1.0 L · 2200 W · from 20 °C · boiling at 100.0 °C

Keetle runs this same calculation on your phone and counts it down on the Lock Screen. See it →

Water

litres

Kettle power

Starting temperature

°C — tap water is usually 10–20 °C

Altitude

metres above sea level

Kettle efficiency — 85%

Most electric kettles land near 85%. The rest heats the jug, escapes as steam, and leaks into the room.

Units

The working

Heating water is one equation. t = m·c·ΔT / (P·η)

Water mass (m)	1.00 kg
Specific heat of water (c)	4186 J/(kg·K)
Temperature climb (ΔT)	80.0 K
Energy needed (m·c·ΔT)	335 kJ
Power actually delivered (P·η)	1870 W
Time	179 s

Boiling point where you are

100.0 °C

At sea level, water boils at 100 °C.

Same water, a UK kettle

2:09

3000 W from a 13 A plug at 230 V.

Both of those have a longer answer — why the wall decides it, and why altitude speeds the kettle up while slowing the cooking: the write-up →

What temperature you actually want

Most of what people brew does not want boiling water.

Drink	Water
Green tea	70–80 °C
White tea	75–85 °C
Matcha	70–80 °C
Oolong	85–95 °C
AeroPress	80–92 °C
Pour-over coffee	90–96 °C
French press	92–96 °C
Black tea	95–100 °C

Reference only — nothing here is computed. Why boiling water ruins green tea, and how to land on these without a variable-temperature kettle, is in the write-up.

If you want this on the kettle itself

Keetle recognises your kettle model, corrects for your altitude automatically, and puts the remaining time on the Lock Screen and Dynamic Island. Everything on this page works without it — nothing here is a teaser.

Scan with the phone you'd actually boil water next to.