Gas Mark, fan oven, conventional oven and Fahrenheit all show up across curing, tempering and workshop processes on this site - anodising dye and seal temperatures, Loctite cure schedules, powder coat and paint cure specs are all quoted in one scale or another depending on the source. This page converts between all four and gives the standard reference chart.
Celsius / Fahrenheit
Straight Temperature Conversion
Gas Mark ↔ Oven Converter
Convert From
Full Reference Chart
| Gas Mark | °C Conventional | °C Fan | °F | Typical Description |
|---|---|---|---|---|
| ¼ | 110 | 90 | 225 | Very cool |
| ½ | 120 | 100 | 250 | Very cool |
| 1 | 140 | 120 | 275 | Cool |
| 2 | 150 | 130 | 300 | Cool |
| 3 | 170 | 150 | 325 | Warm |
| 4 | 180 | 160 | 350 | Moderate |
| 5 | 190 | 170 | 375 | Moderately hot |
| 6 | 200 | 180 | 400 | Fairly hot |
| 7 | 220 | 200 | 425 | Hot |
| 8 | 230 | 210 | 450 | Hot |
| 9 | 240 | 220 | 475 | Very hot |
| 10 | 250 | 230 | 500 | Very hot |
Where This Matters On This Site
A couple of places this comes up directly in workshop processes covered elsewhere on the site:
→ Anodising: dye bath (55-65°C) and sealing (boiling water or 80°C nickel acetate)
→ Loctite Guide: 250°C removal heat for permanent grades
Common Questions
Gas Mark predates domestic thermostats and was originally a rough setting on a gas cooker's regulator rather than a measured temperature. The Celsius and Fahrenheit equivalents published against it are a standardised approximation, not a physical conversion - which is why this page uses the published reference table with interpolation between points rather than a single formula.
Roughly 20°C below the conventional figure for the same result - a recipe or process spec given as Gas Mark 4 / 180°C conventional is about 160°C on a fan setting. Use the converter above rather than the rule of thumb where the figure actually matters, since the exact offset varies slightly by oven.
No. It's the standard published UK equivalence, close enough for cooking and most workshop curing purposes, but individual ovens can run 10-15°C off their dial setting even when correctly calibrated. For anything where under- or over-curing has a real consequence, check actual chamber temperature with a separate thermometer rather than relying on the dial or this conversion alone.