Temperature Converter
Convert between Fahrenheit, Celsius, and Kelvin for cooking and baking. Essential for following international recipes.
Reviewed by the Calcura editorial team · Last reviewed
- Question
- How do I convert between Fahrenheit, Celsius, and Kelvin?
- Answer
- Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Celsius to Fahrenheit: °F = (°C × 9/5) + 32. Celsius to Kelvin: K = °C + 273.15. Common oven references: 350 °F = 177 °C, 375 °F = 190 °C, 400 °F = 204 °C. Water freezes at 0 °C / 32 °F / 273.15 K and boils at 100 °C / 212 °F / 373.15 K.
▸Show formula & caveatsHide formula & caveats
- Formula
°C = (°F − 32) × 5/9; K = °C + 273.15- Caveats
- Oven dials are usually marked at 25 °F increments; round converted temps to the nearest 5 °F for practical use.
- Kelvin has no negative values and no degree symbol — it's just 'K'.
- UK recipes use gas mark numbers — gas mark 4 ≈ 180 °C ≈ 350 °F.
Oven Temperature Conversion Table
Common cooking and baking temperatures in Fahrenheit, Celsius, and UK gas marks.
| Fahrenheit | Celsius | Gas Mark | Description |
|---|---|---|---|
| 225 °F | 107 °C | ¼ | Very low (slow roast, meringues) |
| 250 °F | 121 °C | ½ | Very low (smoking, slow cook) |
| 275 °F | 135 °C | 1 | Low |
| 300 °F | 149 °C | 2 | Low (slow braise) |
| 325 °F | 163 °C | 3 | Moderate low |
| 350 °F | 177 °C | 4 | Moderate (most baking) |
| 375 °F | 190 °C | 5 | Moderate (cakes, quick breads) |
| 400 °F | 204 °C | 6 | Moderately hot (roasting) |
| 425 °F | 218 °C | 7 | Hot (pastries, pizza) |
| 450 °F | 232 °C | 8 | Hot (pizza, bread crust) |
| 475 °F | 246 °C | 9 | Very hot |
| 500 °F | 260 °C | 10 | Very hot (high-temp pizza) |
What This Calculator Does
This calculator converts temperatures between Fahrenheit, Celsius, and Kelvin using the exact linear formulas. It's the converter for reading a non-native recipe (e.g., an Italian recipe calling for 180°C in a US kitchen) or for calibrating thermometers across scales. For practical cooking, round the output to the nearest 5°F (or 5°C) — oven thermostats rarely resolve finer than that anyway, and most oven dials are calibrated to 25°F increments.
When To Use This Calculator
Following a metric recipe in an imperial oven
A French cookbook calls for '175°C for 25 minutes.' Converted: 175°C × 9/5 + 32 = 347°F, round to 350°F. Close enough for any baked good.
Cross-checking a smart oven reading
A probe reads 63°C for beef medium. Converted: 145°F — matches the USDA 'beef medium-rare' minimum exactly. Useful when the oven's display is in the wrong unit for your reference.
Verifying a meat thermometer in Kelvin
A lab-grade thermometer outputs 338 K during a sous-vide chicken check. Converted: 65°C (149°F) — just above USDA's 63°C (145°F) safe temperature for whole chicken cuts.
Calibrating a thermometer in ice water
An accurate probe should read 32°F / 0°C / 273.15 K when submerged in a well-stirred ice bath. Any reading more than 2°F off the mark means recalibration or replacement.
How It Works
Fahrenheit and Celsius are both degree-based but use different zero points and scale factors: water freezes at 32°F = 0°C, boils at 212°F = 100°C. The linear relationship is °C = (°F − 32) × 5/9, or equivalently °F = °C × 9/5 + 32. Kelvin is a Celsius-sized scale anchored to absolute zero: K = °C + 273.15. The 273.15 offset is exact — 0 K is the theoretical point where molecular motion stops, 273.15 K is the freezing point of water at 1 atm. No approximation is involved in any conversion; rounding only happens when you display the result.
Formula
°C = (°F − 32) × 5/9
°F = °C × 9/5 + 32
K = °C + 273.15
°C = K − 273.15
°F = (K − 273.15) × 9/5 + 32Real-World Example
Scenario
A baker adapting a Paul Hollywood bread recipe that calls for '240°C for the first 10 minutes, then reduce to 220°C for 25 minutes' in a US oven labeled in Fahrenheit.
Calculation
First stage: 240°C × 9/5 + 32 = 464°F → round to 465°F (or max out at 450°F if that's the oven ceiling) Second stage: 220°C × 9/5 + 32 = 428°F → round to 425°F Time unchanged
Result
Bake at 465°F for 10 minutes, drop to 425°F for 25 minutes. The 464→465 rounding is cosmetic; most US ovens step in 25°F increments, so 450°F initial is what most home bakers will actually dial in. Keep the thermometer inside — oven dial accuracy is typically ±25°F even in premium ranges.
Common Mistakes to Avoid
Mistake: Forgetting the 32 offset in F↔C
Solution: A common error is to multiply/divide by 5/9 without subtracting or adding 32. This turns 100°C into 55.6°F instead of 212°F. Always: subtract 32 first when going F→C, add 32 last when going C→F.
Mistake: Confusing convection and conventional temperatures
Solution: European recipes sometimes specify 'fan' or 'convection' temperatures, which are already 15–20°C lower than conventional. Converting a 180°C convection spec and dialing 356°F conventional overbakes. Check whether the source is fan-assisted first.
Mistake: Treating Kelvin as Celsius in cooking contexts
Solution: A probe reading 300 K is 27°C / 81°F — room temperature, not hot. Kelvin is rarely used in culinary contexts; if your display reads in K, subtract 273.15 before interpreting as Celsius.
Mistake: Over-precising the conversion
Solution: 350°F = 176.666…°C exact. Setting an oven to '176.7°C' isn't meaningful — dials step in 5°C or 10°C. Round to the nearest increment your oven supports (usually 175°C or 180°C).
Temperature Converter vs. Related Calculators
Oven Fan Conversion
Converts between fan/convection and conventional oven temperatures (usually a 20°C / 25°F offset). Use after converting units.
Baking Time Adjustment
Adjusts bake time when pan size or batch size changes — separate issue from temperature scale conversion.
Cups to Grams (Flour)
Different kind of recipe conversion (volume to mass). Pair with temperature conversion when adapting a fully metric recipe to a US kitchen.
When This Isn't the Right Tool
Sous-vide precision cooking
Use instead: Sous-vide targets specific °F/°C to 1° precision. Convert with this tool, then dial the immersion circulator to the nearest 0.1°C or 0.5°F — don't round to 5°F increments.
Candy-making and sugar stages
Use instead: Candy stages (soft ball, hard crack, etc.) are narrow temperature bands. Use a calibrated candy thermometer; converting scales doesn't remove the need for the right tool.
High-altitude cooking adjustments
Use instead: At 5,000+ ft, boiling point drops and baking time/temp need adjustment beyond a unit conversion. Use an altitude-specific cooking reference.
Scientific calorimetry or physics
Use instead: For heat-transfer calculations, specific-heat work, or anything involving energy rather than temperature readings, use physics-specific tools. This calculator converts scales only.
How to Verify This Calculation
BIPM's SI brochure lists the exact relationships: K = °C + 273.15 and °F = °C × 9/5 + 32. Cross-check with a reference like 100°C = 212°F = 373.15 K (boiling water at sea level) — any converter that doesn't hit those exactly is wrong.
Sources
- BIPM — SI Brochure (The International System of Units) — Authoritative source for the kelvin and the degree Celsius definitions, including the exact offset 273.15.
- NIST — Thermodynamic Temperature — NIST's plain-language reference for SI temperature units, scale relationships, and calibration practice.
- USDA — Safe Minimum Cooking Temperatures — USDA-recommended internal temperatures for meat, poultry, fish, and leftovers — the practical anchor for most cooking temperature work.
Reviewed by the Calcura editorial team · Last reviewed