Slow Cooker Conversion Calculator
Convert a conventional oven or stovetop cooking time into slow cooker time on the low or high setting.
What you need
7.8hours
On low — The setting to use if you can. Gentler, and far more forgiving of an extra hour.
- On high
- 4.1 hours
Roughly half the low time. Use it when you are short of hours, not for tough cuts.
Guide figures. Ingredient weights, pan sizes and cooking times all vary — see the assumptions below for the ones used.
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How to use the slow cooker conversion calculator
Almost any braise, stew or pot roast can move to a slow cooker, but the time does not scale by a simple multiple — a slow cooker takes hours to come up to temperature whatever you put in it, so a 20 minute simmer does not become a 40 minute one. Enter the conventional time from the recipe.
Why the conversion is not a straight multiple
A hot oven puts a pot at temperature within minutes. A slow cooker on low can take two to three hours to get there, and that ramp is a fixed cost that has nothing to do with the recipe. So the first chunk of any slow cooker time is spent just arriving at a simmer.
That is why a 20 minute conventional braise maps to four to six hours rather than to some tidy multiple of 20. The useful cooking happens after the ramp, and the ramp dominates for short recipes.
What converts well, and what does not
Excellent candidates share a shape: a tough, collagen-rich cut, plenty of liquid, and a long gentle cook that you would not mind extending by an hour. Chuck roast, shoulder, shin, oxtail, dried beans, chilli and stock all improve in a slow cooker rather than merely surviving it.
Poor candidates are lean cuts, quick-cooking proteins and anything textural. Chicken breast goes stringy, fish disintegrates, and pasta turns to paste. If the original recipe takes under 20 minutes on the stove, there is no version of it that benefits from eight hours.
What this calculator assumes
Every estimate depends on figures that vary by supplier and conditions. These are the ones used here, so you can sanity-check the result against your own quote.
- Times come from the standard conversion brackets: 15 to 30 minutes conventional becomes 4 to 6 hours on low or 1.5 to 2 on high; 35 to 45 minutes becomes 6 to 8 low or 3 to 4 high; 50 minutes to 3 hours becomes 8 to 10 low or 4 to 6 high. Values between brackets are interpolated.
- Low and high reach the same temperature — around 209 °F (98 °C) — and differ only in how fast they get there. High is not hotter, so it does not overcook faster once the food is up to temperature; it simply gives collagen less time to break down.
- Reduce the liquid by about a third. A slow cooker is sealed and loses almost nothing to evaporation, so a recipe's full quantity of stock will leave you with a thin, watery sauce.
- Root vegetables cook more slowly than meat in a slow cooker, the reverse of an oven. Put carrots, potatoes and swede at the bottom where it is hottest, and the meat on top.
- Dairy, fresh herbs, peas and pasta go in during the last 30 minutes or they will split, fade or turn to mush.
- This does not apply to baking, roasting, frying or anything that needs dry heat or a browned crust. A slow cooker is a moist-heat device, so brown meat in a pan first if the recipe depends on it.
Frequently asked questions
How long is 1 hour in the oven in a slow cooker?
Roughly 8 hours on low or 4 hours on high. The ratio is not fixed, though — shorter conventional times convert to proportionally longer slow cooker times, because a slow cooker spends the first couple of hours simply getting up to temperature.
Is it better to cook on low or high?
Low, whenever you have the time. Both settings end up at about the same temperature, but low spends far longer in the range where collagen turns to gelatin, which is what makes a tough cut tender rather than merely cooked. High is a schedule compromise, not a shortcut to the same result.
Can I convert a baking recipe to a slow cooker?
Generally no. A slow cooker traps steam, so anything that needs a dry surface — roast potatoes, bread, pastry, anything with a crust — will come out pale and soft. It excels at braises, stews, pulled meats, beans, soups and chilli, where moisture is the point.
Why is my slow cooker meal watery?
Because you used the recipe's full liquid. An oven loses a lot of liquid to evaporation over a few hours and a sealed slow cooker loses almost none, so the original quantity has nowhere to go. Cut liquid by about a third, and if it is still thin, take the lid off for the last half hour on high.
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