---
title: "Floor-height calculator"
description: "Add your flooring layers to estimate the finished height change and remaining door gap. Check covering, underlay, adhesive and preparation thicknesses."
canonical: "https://monkeyfloors.com/tools/floor-height-calculator"
language: "en-AU"
---

Tool

# Floor-height calculator

Compare the layers coming out with the layers going in, then check a measured door gap.

## Calculate it by hand

Add the installed thickness of the new covering, underlay, preparation and adhesive. Subtract the total thickness being removed. A positive result means the new floor is higher.

Subtract that height change from the measured current door gap. This is an arithmetic estimate; have the installer check door movement, transitions and tolerances on site.

This is a measurement estimate. Have your installer check clearances, transitions and any door requirements on site.

## How this tool works

Height change = the total new installed layers minus the total removed layers. Remaining door gap = your current gap minus that height change.

All measurements are in millimetres. The calculation assumes a common subfloor reference and uses the thicknesses you enter; it does not assess installation suitability.

## Questions, answered

### Do I include attached underlay?

Include it once. If the quoted board thickness already includes the attached pad, do not add that pad again as separate underlay.

### Does a positive door gap mean it is suitable?

No. Door movement, seals, tolerances and any fire-door requirements still need to be checked. The result is arithmetic, not an installation approval.

### What if the subfloor needs levelling?

Use the installed preparation thickness advised by your installer. Where thickness varies, calculate the relevant points separately and check the tightest clearance.

## Goes well with

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Calculate whole packs from your measured area, chosen allowance and pack coverage.

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Five questions about your state, building and floor. See what to ask your committee for in writing.

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Guide

### [Acoustic underlay: the layer that deserves a closer look](https://monkeyfloors.com/acoustic-underlay)

Choose acoustic underlay by floor type, installation method and test evidence. Check thickness, moisture, star claims and strata approval before work.

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