Lobster Boil Calculator
Lobster minutes, water, and salt by weight.
What it does
Boiled lobster rewards rolling water and punishes timid pots: minutes scale with weight while water and salt scale with the crowd. Red shells with opaque meat mark the finish.
The tool above takes per lobster weight with count in pounds or kilos. It returns minutes, water, and sea salt.
The default 1.5 lb lobster boils 12 minutes in 3 quarts with 3 tablespoons of salt. The metric mirror at 0.682 kg matches exactly.
Extension cooking guidance with seafood marketing charts bracket the same weight clocks from 8 minutes at a pound to 20 near three. Sea salted rolling water with headroom keeps temperatures honest.
Time starts at the rolling return, not the lobster drop. Soft shells shave 3 minutes, crowded pots add water first, and grilled or steamed lobsters follow separate clocks.
How to use
- Pick pounds or kilos.
- Type weight per lobster.
- Type the lobster count.
- Read minutes first.
- Read water beside it.
- Read salt last.
Formula
- lb
- Live weight per lobster in lb.
- count
- Lobster count in the pot.
University extension lobster cooking guidance with the Lobster Institute boils lobsters by weight with sea salted rolling water. Marketing board charts bracket the same times: 8-10 at 1 lb through 18-22 at 3 lb. Water near 2 quarts per pound per lobster with a tablespoon of salt per quart keeps pots rolling.
Worked example
Example: 1.5 lb lobster
Imperial defaults: 1.5 lb, 1 lobster.
- Lobster: 1.5 lb live, one only.
- Time: round(4 + 5 x 1.5) = 12 min boil.
- Water: 2 x 1.5 x 1 = 3 qt rolling.
- Salt: 3 qt needs 3 Tbsp sea salt.
- Metric: 0.682 kg matches at 2.8 L.
- Tool shows 12 min boil, 3 qt water, 3 Tbsp sea salt.
Reference table
| Lobster | Time | Water |
|---|---|---|
| 1 lb x 1 | 9 min | 2 qt |
| 1.5 lb x 1 | 12 min | 3 qt |
| 2 lb x 2 | 14 min | 8 qt |
| 0.682 kg x 1 | 12 min | 2.8 L |
Limits
- Hard shell timing base.
- Pot size limits crowds.
- Altitude shifts boiling.
- Grill and steam separate.
Common mistakes
- Timing from the cold drop.
- Skimping water volume.
- Forgetting salt entirely.
- Overcrowding small pots.
- Serving soft shells by hard clocks.
Try it yourself
Quick checks. Answers sit tucked under each question.
1 lb, 1 lobster?
9 min boil in 2 qt with 2 Tbsp salt.
2 lb each, 2 lobsters?
14 min boil in 8 qt with 8 Tbsp salt.
0.5 lb?
Under 0.75 falls below charts: enter 0.75 to 10 lb.
Questions
Minutes per pound?
About 4 plus 5 per pound: 9 at 1 lb, 12 at 1.5, 14 at 2, near 20 at 3.
Water volume?
3 qt per 1.5 lb lobster with room to roll. Crowded pots stall the boil.
Salt ratio?
1 tablespoon per quart, about 1/4 cup per gallon. Sea salt or plain, never iodized pricing.
Done signs?
Bright red shell with opaque firm meat. Antennae pull free on done tails.
Soft shells?
Yes, 3 minutes less for soft shells at the same weights.
Steam same?
No, grill and steam run their own clocks near 18 to 20 minutes. This page boils.