Total price that already includes tax, and the tax rate—net price before tax and tax amount.
You enter a tax‑inclusive gross G and rate R%; net before tax = G ÷ (1 + R÷100); “tax part” = G − net. R must be ≥ 0 and < 1000 in validation.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.