Math question .
I've just assembled a raised garden , a little one .
Its 1200x1200x400 ... how many 20 litre bags of garden mix will I need to fill it ?
I'm hopeless at volume equations
Its 1200x1200x400 ... how many 20 litre bags of garden mix will I need to fill it ?
I'm hopeless at volume equations

jeezzz .
Rather than burying half, why not cut it in half ... thèn you get 2 low garden beds for the price of 1
....!