Get the exact boiling time for soft, medium, jammy, or hard-boiled eggs. Adjusts for egg size, starting temperature, altitude, and cooking method so your yolks come out perfectly every time.
| Step | Duration | Cumulative time | Notes |
|---|
| Doneness | Boil time | Yolk texture | Best for |
|---|
| Egg size | Weight | Soft | Jammy | Medium | Hard |
|---|
| Tip | Why it works |
|---|
| Metric | Value | Notes |
|---|
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Founder & CEO, Toolraxy
Faiq Ur Rahman is a web designer, digital product developer, and founder of Toolraxy, a growing platform of web-based calculators and utility tools. He specializes in building structured, user-friendly tools focused on health, finance, productivity, and everyday problem-solving.
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Water boils at a lower temperature the higher you go, and that changes how long an egg needs. At 6,500 feet, a “10-minute egg” can still come out with a soft center. This calculator adjusts for altitude, egg size, starting temperature, and cooking method so the timing actually matches your kitchen. Enter your setup, get a boil time, and start the built-in timer when the water returns to a rolling boil. It supports imperial and metric units, includes a doneness reference table for every egg size, and adds a short ice bath countdown so you know when to pull the eggs.
How to Use the Egg Boiling Calculator
Pick your unit system. Imperial uses Fahrenheit and inches; metric uses Celsius and centimetres.
Select an egg size. The dropdown lists weights for small through jumbo.
Choose your doneness. Soft, jammy, medium, hard, or extra hard.
Set your starting temperature. Fridge-cold eggs take longer than room-temperature eggs.
Enter your altitude. Sea level is the default.
Choose a cooking method. Boiling, cold start, steaming, or pressure cooker.
Adjust egg count and water volume if you’re cooking a batch.
Hit Start timer when the water reaches a rolling boil.
The calculator starts with a base time for a large, fridge-cold egg at sea level, then adds adjustments for size, temperature, and altitude before applying a method multiplier.
Formula: Boil Time = (Base + Size Adj + Temp Adj + Altitude Adj) × Method Multiplier
Base times for large, fridge-cold eggs: 6.0 minutes for soft, 7.0 for jammy, 8.0 for medium, 10.5 for hard, and 13.5 for extra hard.
Formula: Size Adjustment = (Egg Size Factor − 1) × 3.0
Each size has a factor. Small is 0.85, medium 0.93, large 1.0, extra large 1.08, jumbo 1.16. A jumbo egg adds 0.48 minutes to the base time. A small egg subtracts 0.45 minutes.
Formula: Altitude Adjustment = f(altitude in feet)
Below 1,000 ft: no change. 1,000–3,000 ft: +0.5 min. 3,000–5,000 ft: +1.0 min. 5,000–7,000 ft: +1.5 min. 7,000–9,000 ft: +2.5 min. Above 9,000 ft: +3.5 min.
Room-temperature eggs subtract 1.5 minutes from the total. Cooking method applies a multiplier: cold start is 1.0, steaming is 0.9, and pressure cooking is 0.33. Boiling is 1.0.
The final result floors at 3 minutes minimum and rounds to the nearest 0.25 minute. That’s the number the countdown timer uses.
You’re at 6,500 feet in Flagstaff, cooking 6 jumbo eggs from the fridge. You want hard-boiled yolks for deviled eggs. Your method is standard boiling.
Step 1 : Base time. Hard-boiled large egg at sea level: 10.5 minutes.
Step 2 : Size adjustment. Jumbo factor is 1.16. (1.16 − 1) × 3.0 = +0.48 minutes.
Step 3 : Starting temperature. Fridge-cold, so no adjustment.
Step 4 : Altitude adjustment. 6,500 ft falls in the 5,000–7,000 band. +1.5 minutes.
Step 5 : Method multiplier. Standard boiling, so × 1.0.
Step 6 : Total. 10.5 + 0.48 + 0 + 1.5 = 12.48 minutes, rounded to 12.5 minutes.
Step 7 : Ice bath. 2 to 5 minutes after the timer ends.
So 12.5 minutes at a rolling boil, then straight into ice water. At sea level with large eggs, the same doneness takes 10.5 minutes, the altitude and size together add a full two minutes.
For a large fridge-cold egg dropped into already-boiling water at sea level, soft-boiled takes 6 minutes, jammy takes 7, medium takes 8, hard takes 10.5, and extra hard takes 13.5. Those times shift with egg size, starting temperature, and altitude.
The most common mistake is treating “hard-boiled” as one fixed time. A hard yolk at 10 minutes still has a slightly soft center. A fully set, dry yolk needs closer to 13 minutes. The window between jammy and hard is only a few minutes wide, so a 30-second difference is noticeable in the final texture.
Water boils at a lower temperature as altitude increases. At sea level, water boils at 212°F (100°C). At 5,000 feet, it’s about 203°F (95°C). At 10,000 feet, it drops to around 194°F (90°C). Lower boiling temperature means slower heat transfer into the egg, so eggs need more time to reach the same doneness.
The altitude adjustment in the calculator adds 0.5 to 3.5 minutes depending on elevation. At 6,500 feet, that’s +1.5 minutes for a large egg. Skipping the adjustment is why high-altitude cooks end up with soft centers on what should be hard-boiled eggs.
Only marginally, and not for the reason most people think. Salt raises the boiling point slightly but not enough to matter for a 10-minute cook. Vinegar can help coagulate a cracked egg white so it doesn’t leak into the water. Neither does much for peeling.
The real peeling trick is egg age and an ice bath. Eggs that are 7 to 10 days old peel far more easily than fresh ones because the inner membrane has had time to separate from the shell. An immediate ice bath after boiling contracts the egg slightly and stops the cooking process, which also helps the shell release. Baking soda in the water raises pH and can make peeling a bit easier, which is why it’s a dropdown option.
A home cook wants a dippy yolk every morning. Two large fridge-cold eggs into boiling water, 6 minutes on the timer, straight into a cup. The calculator gives the time and the timer handles the countdown. If the cook is at 3,000 feet, the time shifts to 7 minutes and the yolk still runs.
A ramen home cook needs 7-minute eggs, peeled and halved, with a creamy yolk that holds its shape. Jammy eggs are the hardest doneness to nail because the window is so narrow. The calculator’s timer hits the exact second, and the ice bath stops the cooking before the yolk sets further. A 6-jumbo-egg batch at sea level takes 7.72 minutes, rounded to 7.75.
A batch cook wants 12 hard-boiled eggs that peel cleanly and slice without crumbling. The calculator’s hard setting plus the ice bath and the peeling tips cover the whole workflow. A dozen large eggs in a 6-quart pot need about 4 quarts of water to cover by an inch. Time: 10.5 minutes at sea level, plus 5 minutes in the ice bath.
The table below covers USDA egg sizes, standard boil times, and altitude boiling points. It’s context for the calculator’s output, not a substitute for it. Your stove, pot, and egg freshness shift the numbers a little.
| Egg Size | USDA Weight | Typical Boil Time (Soft / Hard) | Notes |
|---|---|---|---|
| Small | 43 g (1.5 oz) | 5.5 min / 10 min | Rare in US retail |
| Medium | 50 g (1.75 oz) | 5.75 min / 10.25 min | Common in UK and EU |
| Large | 57 g (2.0 oz) | 6 min / 10.5 min | US standard reference |
| Extra Large | 64 g (2.25 oz) | 6.25 min / 10.75 min | Common in US stores |
| Jumbo | 71 g (2.5 oz) | 6.5 min / 11 min | Less common; often sold separately |
| Altitude | Water Boiling Point | Adjustment vs Sea Level |
|---|---|---|
| Sea level | 212°F (100°C) | None |
| 3,000 ft | 206°F (96.7°C) | +0.5 min |
| 5,000 ft | 203°F (95°C) | +1.0 min |
| 7,000 ft | 199°F (92.7°C) | +1.5 min |
| 10,000 ft | 194°F (90°C) | +2.5 min |
For a large fridge-cold egg at sea level, soft-boiled takes 6 minutes, jammy 7, medium 8, hard 10.5, and extra hard 13.5. At 5,000 feet, add one minute. Larger eggs need slightly more time. The calculator handles all of these adjustments.
Water boils at a lower temperature as altitude increases. At 5,000 feet, water boils at 203°F instead of 212°F. The lower heat transfer means eggs need more time to reach the same doneness. Add 0.5 to 1.5 minutes in the 3,000–7,000 foot range.
Barely. Salt raises the boiling point slightly but not enough to affect a 10-minute cook. The practical peeling tricks are using eggs that are 7 to 10 days old, shocking them in ice water, and peeling under running water. Baking soda raises pH and can help a bit more than salt.
Yes, and it takes about a third of the boiling time. A 6-minute soft-boiled egg becomes a 2-minute pressure-cooker egg. Pressure-cooked eggs also peel noticeably more easily because the pressure change forces the membrane away from the shell.
Not required, but it changes the timing. Room-temperature eggs cook about 1.5 minutes faster than fridge-cold eggs. The calculator applies that adjustment automatically if you set the starting temperature to room temperature.
Jammy eggs have a semi-set, creamy yolk. For a large fridge-cold egg at sea level, that’s about 7 minutes in boiling water. Pull them right at 7 minutes and shock them in an ice bath to stop the cooking. The window between runny and fully set is only about 30 seconds wide.
The gray-green ring is iron sulfide, formed when the egg is overcooked or cooled too slowly. It’s harmless but the yolk gets rubbery. Pull the eggs the moment the timer ends and put them in an ice bath for 2 to 5 minutes. Fast cooling prevents the ring.
You can, but the time will be off at higher elevations. If you don’t know your altitude, look it up by city or ZIP code. Most areas below 3,000 feet need no adjustment. Above that, the calculator’s altitude field makes the correction automatic.
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