Windows & Doors
Window Glazing Cost Estimator
Build a costed schedule for a set of windows
Updated July 12, 2026 · Live
What this tool does
Builds a costed bill of materials for a window replacement or new glazing job — glazing units, frames and fitting — with a contingency and a per-window figure.
Enter the window count and size, the glazing, frame and fitting prices and a contingency; the calculator totals the job and the cost per window.
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Formula Used
Builds a costed bill of materials for a window replacement or new glazing job — glazing units, frames and fitting — with a contingency and a per-window figure. It runs entirely in your browser and shows the working, so you can check every step against your own figures.
How the window glazing cost calculator works
Each cost line is the per-window price times the number of windows — glazing, frame and fitting. The three are summed and grossed up by the contingency to a total, and the total is divided by the window count to give a clean per-window figure you can compare against a quote. The glass area is shown alongside for reference.
What you enter
Enter the window count and size, the glazing, frame and fitting prices and a contingency; the calculator totals the job and the cost per window. Every field is editable, and the result recalculates the moment you change a value.
Reading the result
The total is the headline; the per-window figure is what you check line by line against a supplier’s breakdown. Because every price is your own, the estimate tracks your actual market rather than a baked-in average.
Safe by design
This tool sizes glazing, cost and thermal performance — not the structural opening. Sizing a lintel or a load-bearing opening is a structural engineer’s calculation, and this page never attempts it.
Assumptions and limits
Prices are yours to enter — nothing is embedded, because window prices swing with material, size and supplier. The estimate covers the units, frames and fitting you list; scaffolding, making-good and building-control fees are separate and vary by job.
Using it with the rest of BuildMetricLab
This calculator is one step in planning the job. Pair it with the related tools in this category and across BuildMetricLab to go from a single figure to a full costed plan — a sizing figure feeds a cost estimate, a cost estimate feeds a project budget, and each result carries straight into the next tool. Every BuildMetricLab tool runs entirely in your browser — no sign-up, nothing sent to a server, and the formula is shown on the page so the maths can be audited.
Sources & methodology
Builds a costed bill of materials for a window replacement or new glazing job — glazing units, frames and fitting — with a contingency and a per-window figure. Every result is calculated from the values you enter, all inputs are editable, and no time-sensitive prices or rates are embedded.
Frequently asked questions
Why price per window rather than per m²?
Suppliers quote most residential windows as a supplied-and-installed unit price, so per-window keeps the estimate close to a real quote. The glass area is shown for reference.
What contingency should I add?
A 10-15% contingency covers awkward openings, making-good and the occasional surprise. Older properties with rot or out-of-square openings justify the higher end.
Does this include permit fees?
No. Window replacement often requires a local building permit and inspection; fees vary by jurisdiction and are entered separately if you need them.
Can I mix window sizes?
This uses an average size for the glass-area figure. For very mixed jobs, run it per window type and add the totals.
Spotted something off?
Calculations or display — let us know.