Slow Cooker Conversion Calculator

How Slow Cooker Time Conversions Work

Slow cookers work at two settings. Low runs at about 190°F (88°C) and High at about 300°F (149°C). Because the pot is sealed, the food itself ends up at the boiling point of water (212°F / 100°C) on either setting. What changes is how long it takes to get there, and that changes a lot.

Time conversion rule of thumb:

Slow cooker HIGH ≈ 2 hours + your oven or stovetop time Slow cooker LOW ≈ 4 hours + twice your oven or stovetop time

Those two lines are the same rule written twice, which is the neat part: (240 + 2t) is exactly double (120 + t), so Low always takes precisely twice as long as High, at any recipe length. That is the ratio every slow cooker manual gives, and it is worth knowing because it means you can switch settings mid-cook and halve or double whatever time is left.

Common conversion table, being what the formula returns at a 350°F recipe:

Those are single numbers rather than ranges because a formula gives one answer. The conversion chart that circulates instead gives bands, and the slow cooker time converter works from that chart, taking your original cooking method into account rather than the oven temperature. Both hold the 2:1 rule, so they never disagree about which setting is twice the other.

They do disagree about the stretch. The chart runs longer in the middle of the range, by as much as two hours on Low for a one to two hour recipe, and the two meet again at four hours. The chart is roughly logarithmic in the original time and this formula is linear, and neither is measured, so pick whichever you find easier to remember. Start at the shorter answer and check the meat: a slow cooker will hold a finished dish happily for another hour, and cannot un-cook one you left too long.

Worked example, beef stew:

A stovetop beef stew simmers for 2 hours. Converting to slow cooker:

• High: 4 hours
• Low: 8 hours, which is exactly double, as it always is

Oven temperature to slow cooker conversion:

If the recipe calls for a specific oven temperature, this is the guide:

• Below 300°F (150°C): use Low
• 300 to 350°F (150 to 175°C): use High, or Low with extra time
• Above 350°F (175°C): a slow cooker cannot do this. It has no dry heat and no browning, so a recipe built around a hot oven will come out pale and stewed rather than roasted

The calculator applies that guide and tells you which setting to use, rather than leaving you to look it up.

Critical tips:

• Do not lift the lid. Each peek adds 15 to 20 minutes, because the pot has to climb back to temperature from cold air
• Fill level matters: slow cookers work best between half and three-quarters full
• Dairy and pasta go in for the last 30 minutes only. Both turn grainy or mushy over hours
• Root vegetables go on the bottom, where the heat is, because they are the slowest thing in the pot
• Thaw frozen meat first. Frozen meat chills the pot and can hold the contents in the 40 to 140°F danger zone for hours, which is a food safety problem rather than a texture one