How Long Does Lobster Take to Cook? A Simple Cooking Time Guide

Cooking whole lobster at home can be surprisingly straightforward, but one question comes up again and again:

How long should you cook a lobster?

The answer depends on the lobster's size and the cooking method you're using.

At Tenby Lobster Co., our standard live Welsh lobsters average approximately 800g each, so understanding cooking time by weight is particularly useful when preparing one of our lobster boxes.

Here's what you need to know.

How Long Does It Take to Cook a Whole Lobster?

Whole lobster can be cooked using several methods, with boiling being one of the most familiar.

As a general guide, an approximately 800g whole lobster may take around 12–15 minutes to boil once the water has returned to a proper boil.

Larger lobsters require more time.

Treat timings as a guide rather than relying on the clock alone. Pan size, water volume, lobster size and cooking method can all affect the result.

For the complete preparation process, read How to Cook a Whole Lobster at Home.

How Long Do You Boil an 800g Lobster?

For an approximately 800g lobster, allow roughly 12–15 minutes of boiling time after the water has returned to the boil.

Make sure you're using a pan large enough to accommodate the lobster comfortably.

If you're cooking several lobsters together, the temperature of the water can drop considerably when they're added, so wait until the water returns to a strong boil before timing.

How Long Does a 1.2kg Lobster Take to Cook?

A lobster over 1.2kg will generally need longer than an 800g lobster.

As an approximate guide, a lobster around this size may require roughly 18–20 minutes when boiled.

Again, size isn't the only variable, so check the lobster is properly cooked rather than relying solely on a timer.

If you're ordering one of our larger lobsters, you can contact Tenby Lobster Co. if you need advice about the particular size supplied.

Lobster Boiling Time by Weight

As a simple starting guide:

*Approximate guidance only. Cooking conditions and lobster size vary. Ensure the lobster is fully cooked before serving.

When Do You Start Timing Boiled Lobster?

This is an important detail.

Adding cold lobster to boiling water causes the water temperature to drop.

Rather than immediately starting your timer the moment the lobster enters the pan, allow the water to return to a proper boil and then begin timing.

Avoid overcrowding the pan, as this can make temperature control more difficult.

How Can You Tell When Lobster Is Cooked?

Don't rely on shell colour alone.

Although the shell becomes a vivid red during cooking, you should also check the meat.

Cooked lobster meat should be opaque and firm rather than translucent, while still remaining tender.

Overcooking lobster can make the meat tougher, which is why getting the timing right matters.

Can You Overcook Lobster?

Yes.

Lobster meat is naturally tender when cooked correctly, but leaving it cooking for too long can make the texture firmer and more rubbery.

This is one reason it's useful to know the approximate weight of your lobster before you begin.

Our standard lobsters average around 800g, although natural variation should always be expected.

Do Larger Lobsters Take Longer to Cook?

Yes. As a general rule, the larger the lobster, the longer it requires.

Tenby Lobster Co. can also source larger lobsters over 1.2kg, subject to availability.

If you're cooking different-sized lobsters, avoid assuming they'll all be ready at precisely the same moment.

How Long Do Lobster Tails Take to Cook?

Lobster tails cook much more quickly than a whole lobster because you're dealing with a smaller portion.

The exact time depends on the size of the tail and whether you're baking, grilling or boiling it.

Our How to Cook Lobster Tails at Home guide covers the different methods in more detail.

What Should I Do Before Cooking a Live Lobster?

If your lobster has arrived before you're ready to cook, it needs to be handled and stored appropriately.

Follow the care instructions supplied with your delivery rather than leaving live lobster at room temperature or placing it in fresh water.

Read our Lobster Care information and How to Store Live Lobster Before Cooking guide before your delivery arrives.

What Do You Do After Cooking Lobster?

Once your lobster is cooked, you'll need to remove the meat from the shell.

The tail and claws contain the most obvious portions, but there's delicious meat elsewhere too.

Our How to Crack and Eat a Whole Lobster guide takes you through the process.

Then it's time to decide how you're serving it.

What Should You Serve with Cooked Lobster?

Lobster doesn't need complicated accompaniments.

Try serving it with lemon, melted butter, new potatoes, fresh bread, seasonal vegetables or a crisp salad.

See What to Serve with Lobster for more ideas.

If you want something richer, try our Garlic Butter Lobster Recipe.

And for a special occasion, our What Wine Goes with Lobster? guide covers wine and Champagne pairings.

Cooking Lobster for Several Guests

If you're cooking lobster for a group, planning your quantities before ordering makes the process much easier.

Our How Much Lobster Do You Need Per Person? guide can help with portions.

For larger gatherings, you can also read How to Plan the Perfect Lobster Dinner Party.

Order Live Welsh Lobster

Tenby Lobster Co. offers lobster boxes suitable for different numbers of guests, from The Coastal Duo for two through to The Pembrokeshire Grand for larger celebrations.

You can browse our live Welsh lobster collection and choose the box that best suits your meal.

Our lobster is sourced from the Pembrokeshire coast and available for live Welsh lobster delivery across mainland UK.

Once your lobster arrives, all that's left is to get the pan ready.

Live • Local • Exceptional.