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Defrost in the fridge on the bottom shelf, breast up, in a tray deep enough for the drip (raw poultry juice is the fridge's biggest hazard). Fully defrosted = no ice crystals in the cavity and legs that move freely. Once defrosted, cook within 24 hours (fridge-thawed keeps up to 2 days). NEVER defrost in a warm room or hot water, and never refreeze raw once thawed.
What The Turkey Defrost Calculator Works Out
- Defrost time: weight x hours per kilo for where it is thawing. Fridge thawing at about 4C runs 10-12 hours per kilo, so a 5kg family bird wants two and a half days and a 9kg showpiece four. A cool room at 3-4 hours per kilo exists for birds too big for the fridge, but only if the room is genuinely under 17C.
- Take it out of the freezer: the defrost time rounded up to whole days before Christmas Day cooking: the 22nd or 23rd for most birds. Leave it on the bottom shelf, breast up, in a tray that catches every drip.
- Check before cooking: no ice crystals in the cavity, legs that move freely, giblets out. A part-frozen bird cooks unevenly; if in doubt allow longer and confirm with a probe thermometer.
- Weight in pounds (advanced): enter the label weight in lb and it is converted (1lb = 0.4536kg) for the timings.
- Cooking day and oven time (advanced): turns the hours into an actual freezer-to-fridge deadline with a day and time, counting back from when the bird goes in the oven on Christmas Day, Christmas Eve, Boxing Day or New Year's Eve. Choose "another day" to see it as days and hours before.
- Hours per kg override and safety margin (advanced): fine-tune for a colder fridge (12-14 hours per kilo at 1-2C) or add a few hours' buffer. The cost of starting early is nothing; the cost of starting late is a centre-frozen turkey meeting a fixed lunchtime.
- Bird type (advanced): a crown thaws roughly 25% faster than a whole bird of the same weight and a boneless joint faster still, because the thickness, not just the weight, sets the time.
- Cooking time on the day (advanced): uses the standard UK guidance of 20 minutes per kilo plus 70 minutes under 4kg or 90 minutes over, at 180C fan / 190C / gas 5, then 30 minutes resting before carving. Done means 74C in the thickest part.
- Cook by (advanced): fridge-thawed raw turkey keeps 2 days at most once fully defrosted, and ideally is cooked within 24 hours. Never refreeze it raw.
Food safety: Food Standards Agency.