Pricing sources checked October 27, 2026 · How we calculate
How this estimate is calculated: the formula, every input and five worked examples.
Illustrative outputs of this site's editorial pricing model (October 2026), not quotes. Change any row or option above to match your house.
Worked example: 20 windows in one job
The preset is a larger two-story house: 10 double-hung windows downstairs, 8 upstairs and 2 picture windows, in vinyl with Low-E glass, insert installation and an average-cost region. The calculator returns $9,300 – $20,400, typical $14,300 for 20 windows (average $720 per window).
| Group | Per window | Group typical |
|---|---|---|
| 10 × Double-hung | $450 – $950 | $6,800 |
| 8 × Double-hung (upper floor) | $500 – $1,060 | $6,000 |
| 2 × Picture | $400 – $1,200 | $1,500 |
Open this example in the whole-house calculator.
The same 20 windows in two phases
Splitting a big job is common when budget is the limit. Here phase 1 is the 8 upstairs windows (often the hardest to maintain), and phase 2 is everything on the ground floor:
| Phase | Windows | Calculator output | Typical |
|---|---|---|---|
| Phase 1: upstairs | 8 double-hung (upper floor) | $4,000 – $8,500 | $6,000 |
| Phase 2: ground floor | 10 double-hung + 2 picture | $5,300 – $11,900 | $8,300 |
| Both phases added | 20 | $9,300 – $20,400 | $14,300 |
| One job (preset) | 20 | $9,300 – $20,400 | $14,300 |
In the calculator the two routes come out essentially the same (any gap is just $50 rounding), because the model has no volume discount. Real quotes usually don't work that way. Angi says replacing all windows at once is generally more cost-effective because contractors can lower per-window labor and material costs and charge overhead once, and it recommends at least five to eight windows per phase (Angi, October 15, 2026). Treat the phased figures as a floor, and ask installers to quote both the full job and phase 1 so you can see the real difference.
Insert or full-frame across 20 windows
On a larger job, the installation method is the biggest lever after frame material. The same 20 windows as full-frame come to $11,650 – $25,550, typical $17,900, which is $3,600 more than inserts at the typical point. Many houses need a mix: inserts where frames are sound, full-frame where they're rotted. Price the rotted openings as a separate run; the full-frame vs. insert calculator shows the per-window gap.
Planning a phased project
- Pick one product line and color for both phases so the house matches; manufacturers update lines over time.
- Ask whether the phase 1 price can be held for phase 2, and for how long.
- Group each phase by floor or elevation so the crew sets up staging once per phase.
Other quick estimates by window count
For any other mix, use the whole-house calculator or the main calculator. Every formula and multiplier is on the methodology page.
Frequently asked questions
How much does it cost to replace 20 windows?
For 10 ground-floor and 8 upstairs double-hung windows plus 2 picture windows, in vinyl with Low-E glass and insert installation, this calculator gives $9,300–$20,400, typical $14,300. Full-frame installation raises the typical point to $17,900.
Is it cheaper to replace 20 windows at once or in phases?
Usually at once. This calculator doesn't model a volume discount, so both routes come out about the same here, but Angi says contractors often lower per-window costs on larger jobs and charge overhead once.
How should I split a 20-window project?
Start with failed, leaking or upper-floor windows, keep at least five to eight windows per phase, and use the same product line throughout.