Thawing Time Calculator

Written byOleh Soloninupdated 27 September 2026

Food

Weight, kg

Method

Result

Thawing time24 h
In the fridge24 h
In cold water2 h 29 min
Where the figures come fromper USDA FSIS "The Big Thaw"
Fooda joint of meat
Hours24
What matters
Fridge thawing is the safest route: the food never rises above +5 °C. Raw food thawed this way can be refrozen, with some loss of quality.

Hours per kilogram

Works out how long meat, poultry, fish or pastry takes to thaw in the fridge or in cold water, and flags the methods that are not safe.

Thawing is not 'leave it on the counter'. Between 5 and 60 degrees bacteria multiply quickly, and while the centre of a joint is still frozen the surface can spend hours in that range. That is why the US Food Safety and Inspection Service (USDA FSIS) names only the fridge, cold water and the microwave as safe.

The calculator follows USDA FSIS ("The Big Thaw"): in the fridge at least a day for every 5 pounds, and even a pound of mince or boneless breast needs a full day; in cold water about 30 minutes per pound for a whole bird and 2 to 3 hours for a 3-to-4-pound pack. In practice the thickness and the fridge temperature matter too.

How to use

Pick the food and enter its weight in kilograms.
Compare the two methods: in the fridge and in cold water.
Count backwards from when you want to cook — the fridge is the slowest route and the safest.
Do not thaw at room temperature: the surface warms up long before the middle does.

How long a piece takes in the fridge

Each row is a run of this calculator for a joint of meat. Even a small piece takes a full day in the fridge, and beyond that the time grows with the weight — a day for every 2.3 kg.

Cold water is much faster, because water moves heat far better than air does, but the food must be cooked straight after. The food has to sit in a sealed bag, though, or it takes on water and loses flavour.

Runs of this calculator for a joint of meat.
Weight	In the fridge	In cold water
0.5 kg	24 h	50 min
1 kg	24 h	1 h 39 min
1.5 kg	24 h	2 h 29 min
3 kg	32 h	4 h 58 min

What this calculator shows

The thawing time for your weight by the method you chose
The fridge and the cold-water route side by side in hours
What has to be observed for the method to stay safe

What to keep in mind

The fridge is taken at +2 to +5 °C — the top shelf runs warmer and faster, and less safely.
Cold-water thawing assumes a sealed bag and a change of water every 30 minutes; without that the water warms and the method loses its point.

FAQs

How long does a chicken take to thaw in the fridge?

Per USDA, at least a day for every 2.3 kg, and even a small chicken needs a full day. Take a 1.5 kg bird out of the freezer the day before you cook it.

Can I thaw at room temperature?

Better not. The surface reaches an unsafe temperature within a couple of hours while the middle is still frozen. Cold water in a sealed bag, changed every half hour, is the safe fast route — with cooking straight after.

Can I refreeze thawed food?

After thawing in the fridge, yes, even raw, though the quality suffers a little (USDA FSIS). After cold water or the microwave, cook it first.

How do I speed thawing up safely?

A sealed bag and cold water, running or changed regularly. Change the water every 30 minutes and cook the food as soon as it has thawed (USDA FSIS).

Why the fridge rather than the worktop?

Because at room temperature the surface spends hours warm while the middle is still frozen. In the fridge the whole piece stays in a range where microorganisms barely multiply.

Can I refreeze what I have thawed?

Raw, if it was thawed in the fridge: USDA FSIS allows it, with some loss of quality. After cold water or the microwave, cook it first. Cooking does not rescue food thawed unsafely, though: some bacterial toxins, staphylococcal ones among them, survive heat.

Worked example

A 1.5 kg chicken

Input: Whole bird, 1.5 kg, fridge

Output: 24 hours

Note: USDA allows no less than a day in the fridge, so a chicken for tonight comes out of the freezer the day before. In cold water the same bird thaws in about 1 hour 40 minutes, but the water needs changing every half hour and the bird cooking straight away.

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Result

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