I am putting in a new toilet connecting into original soil pipe,how much fall is required for the waste pipe?

I am putting in a new toilet connecting into original soil pipe,how much fall is required for the waste pipe?
Standard minimum is 1" over 4', or 1/4" per foot.

The required fall is 1/4 inch to the foot, however, if elevation's tight and there's no way you can't manage 1/4" to the foot 1/8" is acceptable on larger drain lines.. Good luck, Tom