Oven temperatures · gas mark guide

170°C to gas mark

170°C is gas mark 3 and 325°F on recipe charts (338°F exactly). Check if your recipe means a fan oven: if 170°C is the fan temperature, the conventional equivalent is 190°C, which is gas mark 5.

Chart checked against Delia Smith and Waitrose on .

Gas mark

3

on the chart

Fahrenheit

325°F

338°F exactly

Fan oven

150°C

if 170°C is conventional

If 170°C is fan

Gas 5

190°C conventional

Gas mark conversion chart

The row nearest to 170°C is gas mark 3.

Gas markConventionalFanFahrenheitHeat
Gas ¼110°C90°C225°FVery cool
Gas ½120°C100°C250°FVery cool
Gas 1140°C120°C275°FVery low
Gas 2150°C130°C300°FVery low
Gas 3170°C150°C325°FLow
Gas 4180°C160°C350°FModerate
Gas 5190°C170°C375°FModerately hot
Gas 6200°C180°C400°FHot
Gas 7220°C200°C425°FHot
Gas 8230°C210°C450°FVery hot
Gas 9240°C220°C475°FVery hot

Conventional or fan?

UK recipes often give two figures, such as 200°C or 180°C fan. If yours just says 170°C, it usually means a conventional oven, so a fan oven should be set to 150°C and a gas oven to gas mark 3.

Exact conversion

170°C × 9 ÷ 5 + 32 = 338°F. The closest gas mark on the chart is gas mark 3, which is 170°C and 325°F.

What cooks at 170°C

Gas mark 3 is a low oven, the usual setting for casseroles, shortbread and slower-baked cakes. The settings either side are gas mark 2 (150°C, 300°F) and gas mark 4 (180°C, 350°F).

Other temperatures

gas mark 3 in full · Full gas mark conversion chart · Convert any temperature

Common questions

What gas mark is 170°C?

Gas mark 3.

What is 170°C in a fan oven?

150°C, if the recipe's 170°C is for a conventional oven.

What gas mark is 170°C fan?

A fan setting of 170°C matches 190°C in a conventional oven, which is gas mark 5.

What is 170°C in Fahrenheit?

338°F exactly, but recipes treat 170°C and 325°F as the same setting.

Sources and assumptions

  • Conventional means an electric oven with the fan off. Fan settings are 20°C lower.
  • Recipe charts round temperatures to the nearest 10°C or 25°F, so exact conversions differ by a few degrees.

Ovens vary. An oven thermometer shows what yours is really doing.