Converting Extract Recipe to All Grain

[mshergold]

Hi. I need to convert this recipe into all grain. Can anyone help me with a formula? I've looked around online, but am not convinced by the formulas I've found.

[Brotherton Lad]

I don't know a formula, but 4kg or 4.25kg Maris Otter should do the trick. Keep everything else the same.

[mshergold]

Thanks!