Calcolatore di Isolamento

Ultimo aggiornamento: 2026-05-07

Usa il Calcolatore di Isolamento per ottenere risultati precisi. Inserisci i valori qui sotto.
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Common Sizes — Click to Fill
Lunghezza parete (m) Larghezza rotolo (cm) Lunghezza rotolo (m) Altezza parete (m)
Small room 4 m 30 cm 10 m 2.7 m
Medium room 6 m 30 cm 10 m 2.7 m
Large room 8 m 40 cm 10 m 2.7 m
Office 12 m 55 cm 10 m 2.7 m
Warehouse 16 m 75 cm 10 m 2.7 m

What is the Insulation Batt Calculator?

Proper insulation is one of the highest-ROI home improvements you can make — the right amount can cut heating and cooling bills by 20–30%. But calculating how many insulation rolls or batts you need for walls, floors, or ceilings requires knowing the stud spacing, roll dimensions, and the 10% waste factor that most guides forget to mention. This calculator handles all of it automatically.

You may also find the Drywall Calculator, Wallpaper Calculator, and Roofing Shingle Calculator useful.

Who Uses This Calculator?

This tool is used by homeowners insulating a new build or retrofit, builders specifying insulation for a project, and energy auditors calculating upgrade requirements.

How to Use the Insulation Batt Calculator

  1. Enter your Wall length.
  2. Enter your Wall height.
  3. Enter your Stud spacing.
  4. Enter your Roll width.
  5. Enter your Roll length.
  6. Click Calculate to see your results instantly.

Formula

The calculator uses the following formula:

Wall area = Length × Height; Rolls = ceil(area ÷ (roll_width × roll_length) × 1.1)

Worked Example

A 15 m × 2.4 m wall section with 600 mm stud spacing using rolls that are 600 mm wide × 2.4 m long requires 28 rolls including the 10% waste allowance.

Step-by-Step Calculation

  1. Wall area: 8 m × 2.7 m = 21.6 m²
  2. Coverage per roll: 0.38 m × 10 m = 3.8 m²
  3. Rolls needed: ceil(21.6 ÷ 3.8 × 1.1) = 7 rolls

Common Mistakes to Avoid

  • Using stud spacing in metres instead of centimetres
  • Forgetting to add 10% extra for cuts around windows and doors
  • Not checking if the roll width matches your stud spacing
Pro Tip: Match the insulation width to your stud spacing exactly — 400 mm batts for 400 mm centres, 600 mm for 600 mm centres. Batts that are too narrow leave cold gaps; too wide and they compress, reducing R-value.

Frequently Asked Questions

What R-value do I need?

R-value requirements depend on your climate zone and building element. As a guide: walls typically need R2.0–R2.5, ceilings R3.5–R6.0, and underfloor R1.5–R2.5 in temperate climates. Cold climates need higher values.

What is the difference between batts and rolls?

Batts are pre-cut to standard lengths (usually 1.2 m or 2.4 m) for easy installation between studs. Rolls are continuous and can be cut to length — better for irregular spaces and large open areas like attics.

Why add a 10% waste factor?

Insulation must be cut around electrical outlets, pipes, and structural members. Off-cuts from windows and doors also generate waste. 10% is the industry standard; add 15% for complex layouts.

Can I double up insulation layers for more R-value?

Yes — stacking two layers of R2.0 gives R4.0. In ceilings, you can lay a second layer perpendicular to the first to also eliminate thermal bridging at the joists.

How do I insulate around electrical boxes?

Split the batt behind the box so it fills the wall cavity on both sides. Never compress insulation tightly behind a box — it creates a fire risk. Some codes require specific fire-rated insulation around recessed lights.

Scritto e revisionato dal team editoriale di CalcToWork. Ultimo aggiornamento: 2026-05-07.