How is the slow cooker time calculated?

The calculator uses the three-band table published in major slow-cooker cookbooks and culinary guides: conventional times of 15–30 minutes map to LOW 4–6 hours / HIGH 1.5–2 hours; 30–45 minutes map to LOW 6–8 hours / HIGH 3–4 hours; and 45 minutes to 3 hours map to LOW 8–12 hours / HIGH 4–6 hours. These ranges reflect the wide variation in slow-cooker wattage and recipe density, so always check at the lower bound of the range.

Why do I need to reduce the liquid?

A conventional oven or uncovered stovetop lets steam escape, so recipes are designed expecting significant evaporation. A slow cooker has a tight-fitting lid — moisture condenses on the inside and drips back into the pot. Using the full original liquid amount results in a watery, diluted sauce. The calculator reduces liquid by 33% on LOW and 25% on HIGH, following the guidance in resources such as America's Test Kitchen's Slow Cooker Revolution.

How do I decide between LOW and HIGH?

LOW (roughly 90 °C / 195 °F internal liquid temperature) produces a deeper, richer flavour and is better for tough cuts like brisket, shoulder, and oxtail because the extended time breaks down collagen fully. HIGH (roughly 150 °C / 300 °F) is faster but produces similar results for most dishes. Choose LOW if you want to set it in the morning and eat in the evening; choose HIGH if you need dinner in 4–6 hours.

What oven temperatures suit the slow cooker?

Oven temperatures at or below 160 °C (320 °F) correspond well to LOW — these are gentle braise temperatures. Recipes running at 160–200 °C translate to HIGH. Recipes above 200 °C (400 °F) should be adapted to HIGH with a Maillard browning step first: sear the meat or vegetables in a hot pan for 2–3 minutes per side before transferring to the slow cooker, otherwise the dish lacks the caramelised crust and depth that high-heat roasting creates.

Can I convert baking recipes like bread or cake?

Most baked goods rely on dry heat and steam release for crust and rise — a slow cooker cannot replicate this. Slow-cooker "bakes" exist (brownies, fudge cakes, bread puddings) but they work via steam and produce a moist, pudding-like texture rather than a crisp bake. This calculator is designed for wet braises, stews, casseroles, soups, and roasting-style dishes where liquid is present.

When should I add dairy, pasta, or seafood?

These ingredients overcook badly under extended slow heat. Add cream, milk, sour cream, hard cheese, pasta, rice, and shellfish only in the last 30 minutes of the cook on HIGH or the last 60 minutes on LOW. Stir in dairy off-heat if possible to prevent curdling. The calculator notes this in the results panel as a reminder.

Slow Cooker Conversion Calculator

A slow cooker is one of the most forgiving appliances in any kitchen — but simply halving the heat or tripling the time from an oven recipe rarely works. This slow cooker conversion calculator applies the correct culinary rules for time, temperature, liquid reduction, and serving scale so your first attempt comes out right.

How the conversion works

Slow cookers operate at two standardised internal liquid temperatures:

LOW — approximately 90 °C / 195 °F — just above a gentle simmer. This is ideal for tough, collagen-rich cuts (brisket, shoulder, shank) because the prolonged heat slowly dissolves connective tissue into silky gelatin.
HIGH — approximately 150 °C / 300 °F — a gentle braise. Most dishes cooked on LOW can be cooked on HIGH in roughly half the time with similar results.

The tool recommends a setting based on your original oven temperature. Recipes baked below 160 °C are already in gentle-braise territory and map naturally to LOW. Anything above 160 °C maps to HIGH. Recipes above 200 °C (roasts, gratins, bakes) additionally benefit from a brief pan-sear before the slow cooker step to replicate the Maillard crust the oven would have produced.

Time conversion formula

The time calculation uses the industry-standard three-band table:

Conventional cook time	Slow cooker LOW	Slow cooker HIGH
15–30 minutes	4–6 hours	1.5–2 hours
30–45 minutes	6–8 hours	3–4 hours
45 minutes – 3 hours	8–12 hours	4–6 hours

These bands appear in the BBC Good Food Slow Cooker guide, America’s Test Kitchen Slow Cooker Revolution, and numerous manufacturer handbooks. The wide ranges exist because slow-cooker wattage varies significantly (120 W to 320 W) and ingredient density affects heat distribution. Always check doneness at the bottom of the range.

Liquid reduction

Conventional oven and stovetop recipes are written assuming substantial evaporation. A slow cooker’s sealed lid returns condensed steam to the pot — there is no net liquid loss during cooking. If you use the full original liquid quantity, the finished dish will be thin and watery.

The calculator applies:

LOW: reduce liquid by 33% (longer cook, more condensation cycles)
HIGH: reduce liquid by 25% (shorter cook, less recirculation)

These percentages match the guidance in America’s Test Kitchen’s extensive slow-cooker testing. After cooking you can always reduce the resulting sauce on the stovetop for 5–10 minutes if you want a thicker consistency.

Serving scale

Divide the desired servings by the original servings to get a linear scale ratio. All ingredient quantities — including the already-reduced liquid — are multiplied by this ratio. Most slow cookers hold 4–6.5 litres; scaling up by more than 1.5× may overfill a standard unit.

Worked example

A classic beef bourguignon calls for 180 °C / 90 minutes / 500 ml red wine for 4 servings. You want 6 servings and have the whole day free.

Setting: 180 °C > 160 °C → HIGH recommended (or LOW if you prefer). You choose LOW for maximum flavour development.
Time: 90 minutes falls in the 45–180 minute band → LOW: 8–12 hours.
Liquid: scale ratio = 6 ÷ 4 = 1.5×. Scaled wine = 500 × 1.5 = 750 ml. Reduce by 33% → 502 ml in the slow cooker.
Browning step: 180 °C > 160 °C, so sear the beef in batches in a hot pan first, then transfer everything to the slow cooker.
Result: deep, unctuous bourguignon after 8–10 hours on LOW, without a watery sauce.

Tips for success

Do not lift the lid during cooking. Each peek releases steam and drops the temperature, adding 20–30 minutes to your cook time.
Thickeners last: cornstarch or flour slurries should be stirred in during the final 30 minutes on HIGH.
Root vegetables go on the bottom — carrots, potatoes, and parsnips are denser than meat and need direct contact with the hottest part of the pot.
Frozen food: always thaw before adding. Frozen ingredients lower the internal temperature below the safe 63 °C threshold for too long.
Alcohol: wine and spirits do not reduce in a slow cooker. Add 25–50% less than the original recipe and let the finished dish rest with the lid off for 10 minutes if the alcohol flavour is too prominent.