How long will 20kg of propane last?

Hi Folks,

I realise this is an impossible question to answer but I'm keen to get as much insight as possible to help me work out what I do about gas.

We will mainly be 2 travelling together in our main camper but occasionally joined by our 2 kids in our defender. Using gas only for cooking. We will be fitting a three burner stove with oven.

We also drink lots of tea!

I'm currently thinking of chassis mounting a fixed tank and so want to have enough capacity to be able to not be too stressed about refilling. I will carry an MSR for multi day hiking trips which we will be able to use in emergencies but I'd rather have enough capacity to last between fills.

I'd love to hear experience of how long folks last on their supplies.

Thanks is advance.

We use a 13 kg propane tank in our truck for cooking only (3 burner with grill and oven) and it last us about 6 months. That's with hot drinks and cooking on the hob every day, and oven meals a couple of times per week. Cooker is a GN Espace levante, although any compact marine cooker will have similar consumption.