Egg Boiling Timer
Pick your egg size, whether it comes from the fridge, how you like the yolk and your altitude. The timer works out the boiling time and rings when your eggs are ready.
Times are estimates for eggs lowered into water at a rolling boil, then kept at a gentle boil. Stoves, pans and eggs vary, so adjust to taste.
How to use the Egg Boiling Timer
- Bring a pot of water to a rolling boil, with enough water to cover the eggs by about 2 cm (1 in).
- Choose doneness, size, start temperature and altitude; the boiling time updates instantly.
- Lower the eggs gently into the water with a spoon and press Start timer straight away.
- Turn the heat down to a steady, gentle boil while the timer counts down.
- When the alarm rings, move the eggs to ice water to stop the cooking, then peel and enjoy.
Boiled egg times at a glance
For eggs lowered into water that is already at a rolling boil, at sea level. Start the timer as soon as the eggs go in.
| Doneness | Large, from fridge | Large, room temperature | Medium (50 g), from fridge | Jumbo (71 g), from fridge |
|---|---|---|---|---|
| Very soft (dippy) | 5:00 | 4:25 | 4:35 | 5:45 |
| Soft (runny yolk) | 6:00 | 5:15 | 5:30 | 6:55 |
| Jammy | 7:00 | 6:10 | 6:25 | 8:05 |
| Medium | 9:00 | 7:55 | 8:15 | 10:25 |
| Hard | 11:00 | 9:40 | 10:05 | 12:45 |
| Extra hard | 13:00 | 11:25 | 11:55 | 15:05 |
How the boiling time is calculated
Time = base time × size factor × start factor × altitude factor, rounded to 5 seconds.
- Base time is the tested time for a large (57 g) egg from the fridge at sea level, for example 6 minutes for soft.
- Size factor = (egg weight ÷ 57 g)2/3. Heat travels inward, so cooking time grows with the egg's diameter squared, which is proportional to weight to the power 2/3 (as in Charles Williams' egg-boiling formula).
- Start factor is 0.88 for room-temperature eggs, which need about 12% less time than cold eggs.
- Altitude factor uses Williams' formula, t ∝ ln[0.76 × (Tegg − Twater) ÷ (Tyolk − Twater)], with water boiling about 1 °C lower for every 300 m. At 1,500 m (about 4,900 ft) water boils near 95 °C and a hard egg needs about 17% longer.
Example: a jumbo (71 g) egg from the fridge, soft-boiled at sea level: 6:00 × (71 ÷ 57)2/3 = 6:00 × 1.16 ≈ 6:55.
Tips for perfect boiled eggs
- Use eggs that are a week or two old for hard-boiled eggs: very fresh eggs are harder to peel.
- Lower the eggs in gently with a spoon so they don't crack, and use enough water that the boil returns quickly.
- Keep the water at a gentle, steady boil rather than a violent one to avoid cracked shells.
- Chill in ice water right away. It stops the cooking and prevents the gray-green ring around overcooked yolks.
- Peel under running water, starting from the wide end where the air pocket is.
- Food safety: refrigerate hard-boiled eggs within 2 hours and eat them within a week.
Frequently asked questions
How long do I boil an egg for a runny yolk?
A large egg straight from the fridge needs about 6 minutes in boiling water for a set white and a runny yolk, or 5 minutes for a very soft, dippy egg. A room-temperature egg needs a little less.
How long do I boil a hard-boiled egg?
About 11 minutes for a large egg from the fridge, lowered into boiling water. Go to 12 or 13 minutes for an extra-firm yolk, then chill in ice water so the yolk does not turn green.
How long for a jammy egg?
About 7 minutes for a large egg from the fridge. The yolk is soft and sticky in the middle, perfect for ramen and salads.
Why do eggs take longer at high altitude?
Water boils at a lower temperature as altitude increases, roughly 1 °C lower for every 300 m (1,000 ft). At 1,500 m water boils at about 95 °C, so eggs take around 15% longer.
Does egg size change the boiling time?
Yes. Bigger eggs take longer because heat has further to travel to the center. The calculator scales the time with the egg's weight to the power of two thirds, which follows how heat spreads through a sphere.
Why put boiled eggs in ice water?
Ice water stops the cooking so the yolk stays exactly as you timed it, and it makes the shell easier to peel. Leave soft eggs in for about 1 minute and hard eggs for 3 to 5 minutes.
Will the alarm work if I switch tabs?
Yes, the countdown keeps time from the clock, and the alarm plays when it ends. If you allow notifications you also get a pop-up, which helps when the browser is in the background. Keep the device's volume on.