FreeByte

Home efficiency payback calculator

When an upgrade repays itself.

Built and reviewed by Dovanic, Founder and editor, FreeByteLast reviewed: 2026-08-18
$
$
22%

Payback

6.9 yr

Yearly saving

$462

With these inputs, payback comes to 6.9 yr. Yearly saving works out to $462.

Saving over 15 years
$6,930
Net benefit
$3,730

What moves the number · Payback

Input−10%Now+10%
Upgrade cost6.2 yr6.9 yr7.6 yr
Current yearly energy bill7.7 yr6.9 yr6.3 yr
Expected saving7.7 yr6.9 yr6.3 yr

Solve for an input

Whatmakesequal

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Save this set of inputs, change something, then save again to compare the outcomes side by side.

When an upgrade repays itself.

A worked example

Starting figures

Upgrade cost
$3,200
Current yearly energy bill
$2,100
Expected saving
22%

What it returns

Payback
6.9 yr
Yearly saving
$462
Saving over 15 years
$6,930
Net benefit
$3,730

How to read the results

With the defaults above, payback works out at 6.9 yr.

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