Gelcoat Calculator
Work out your gelcoat quantity
Enter your mould's surface area and number of coats below for an instant gelcoat and catalyst estimate.
Common questions
Gelcoat or topcoat — which do I need?
Gelcoat is applied to the mould before laminating, so the finished part takes on the mould's surface. Topcoat is applied after laminating, directly onto the outer face of the part — use our Topcoat Calculator for that instead.
How do I apply gelcoat?
Brush or roller, applying in one direction to avoid trapping air. We only supply brush/roller-grade gelcoat, not spray gelcoat.
How many coats do I need?
Two coats is typical, giving enough build thickness without excessive shrinkage risk. Very detailed or vertical mould faces sometimes need a third light coat.