Window Replacement Cost Calculator

How it is calculated

The estimate is built from glazed area and a flat installed rate per square foot. Width and height are in inches, so one window is area = width × height ÷ 144 sq ft. The rates are fixed in the tool: 30 per sq ft for single, 55 for double and 80 for triple glazing, in US dollars and assuming mid-market vinyl frames. Materials = area × windows × rate, labour = labour per window × windows, and total = materials + labour. Per-window cost is the total divided by the count. Labour per window defaults to 150 only when the field is blank; an entered negative value gives no result, and 0 is accepted. An unrecognised glazing value is treated as double. The window count must be a whole number of at least 1, so 2.7 shows no result, and width or height above 240 in (20 ft) is refused. Frame material, delivery, permits and removal fees are not itemised, and local prices differ.

Common mistakes

• Entering window sizes in centimetres or millimetres. Width and height are inches, so a 90 × 120 cm window is about 35.4 × 47.2 in; typed as 90 × 120 it would be treated as a very large opening, and anything above 240 in is refused.
• Entering the total glass area or the frame size of the whole wall as one window's size. Size is per window, then multiplied by the count.
• Typing a fractional count such as 2.7 expecting it to be priced. Only whole windows are accepted, so there is no result.
• Leaving labour blank and assuming it is zero. A blank field uses the default of 150 per window, so enter 0 if the work is free.
• Treating the figure as a quote. The rates are fixed averages for one frame type, so timber or aluminium frames, bay windows and removal of old units will move the price.