Subfloor Calculator

Determine how many 4x8 plywood or OSB sheets you need to build a subfloor.

Utilisez des decimales si necessaire. Cette estimation se met a jour en direct et peut etre ajustee en toute securite avant l'achat.

Minimum 1 ft. Les nombres entiers donnent l'estimation la plus claire.

Minimum 1 ft. Les nombres entiers donnent l'estimation la plus claire.

Minimum 0. Les nombres entiers donnent l'estimation la plus claire.

L'estimation se met a jour automatiquement pendant la saisie.

Estimated sheets

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Subfloor Buying Guide

This guide helps you turn your subfloor calculator result into a cleaner purchase plan. Use it when you want fewer return trips, better waste assumptions, and a more realistic cart.

Step 1: Always buy Tongue and Groove (T&G)

Subfloor panels must interlock. Standard square-edge panels will flex independently when you walk on them, causing the floor above to crack or squeak.

Step 2: Upgrade to premium OSB

Products like Advantech cost more than standard OSB, but they are highly water-resistant. If it rains during construction, standard OSB edges will swell and require heavy sanding.

Step 3: Stagger the joints

Never align four corners in a grid. Start the second row with a half-sheet so the seams are staggered like a brick wall for maximum structural integrity.

Subfloor cost planning rule of thumb

A squeak-free floor requires the T&G panels, heavy-duty polyurethane construction adhesive for the joists, and a specialized flooring screw gun.

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FAQ Subfloor Calculator

Faut-il arrondir avant d acheter ?

Oui. Une petite marge couvre les coupes, la perte et les ajustements de derniere minute.

La disposition influence-t-elle la perte ?

Oui. Les plans simples demandent moins de marge, tandis que les angles, motifs et obstacles en demandent davantage.