170 °C in Gas Mark

170 °C on a gas oven dial:

gas mark 3–4

Between two dial settings

150 °C

Fan-forced oven

There is no exact gas mark for 170 °C. The dial steps from 160 °C (gas mark 3) to 180 °C (gas mark 4), so this temperature falls between the two. Gas mark 3 gives a gentler bake, gas mark 4 a faster one — the 10 °C either way is smaller than the swing of most domestic thermostats.

Fan-forced ovens run about 20 °C hotter than conventional at the same dial setting, so 170 °C is 150 °C with the fan on. See the full oven temperature conversion chart.

This one has no clean answer, and any chart that gives you a single number is rounding without telling you. The gas ladder steps 160 °C (gas mark 3) then 180 °C (gas mark 4), so 170 °C lands exactly halfway between two rungs with nothing marked on the dial for it.

170 °C in Gas Mark conversion table

Gas markBetween 3 and 4
Conventional oven (°C)170 °C
Fahrenheit (°F)338 °F
Fan-forced / convection150 °C
Oven descriptionModerate

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= gas mark 4

Frequently asked questions

What is 170 °C in gas mark?

There is no exact gas mark for 170 °C — it sits midway between gas mark 3 (160 °C) and gas mark 4 (180 °C). Most recipes converted from 170 °C use gas mark 3 for a slightly gentler bake; choose gas mark 4 if you want it to move a little faster and are happy to check early.

Is 170 °C gas mark 3 or gas mark 4?

Either can be defended, which is why charts disagree. Gas mark 3 is the safer choice for cakes, custards and anything that suffers from a hot oven; gas mark 4 suits roasting and pastry, where a touch more heat helps. The 10 °C either way is smaller than the swing of most domestic thermostats.

What is 170 °C in Fahrenheit?

170 °C is 338 °F exactly. US ovens are marked in 25 °F steps, so there is no 338 setting either — use 325 °F to match gas mark 3, or 350 °F to match gas mark 4.

What is 170 °C in a fan oven?

Set a fan oven to 150 °C. The fan adjustment is always about 20 °C below the conventional temperature, and it applies to 170 °C just as it does to the marked rungs.