Aluminium windows are made to measure, so in theory any aluminium window size is possible. In practice, most Indian homes use a small set of common sizes, because architects and builders work with similar room sizes, sill heights and lintel levels. Knowing these sizes helps you plan rooms, compare quotes on equal terms, and spot an opening that is unusually large or small. Here are the common sizes room by room, along with tips on measuring.
Why Window Sizes Follow a Pattern
In most houses the top of every window and door sits at the same lintel level, typically around 7 ft (2100 mm) from the floor. Windows usually sit on a sill about 2.5 to 3 ft (750 to 900 mm) high. That leaves a window height of roughly 4 ft, which is why 4 ft high windows are so common. The width then depends on the wall and the size of the room.
Common Window Sizes by Room
| Room | Common sizes (W x H) | Notes |
| Bedroom | 4 x 4 ft, 5 x 4 ft, 6 x 4 ft | About 1200 x 1200 mm to 1800 x 1200 mm |
| Living room | 6 x 4 ft to 8 x 5 ft | Wide openings are often split into 3 or 4 shutters |
| Kitchen | 3 x 3 ft, 4 x 3 ft | Sill raised to clear the counter |
| Bathroom | 2 x 1.5 ft, 2 x 2 ft | About 600 x 450 mm or 600 x 600 mm |
| Staircase | 2 x 4 ft, 3 x 4 ft | Often fixed or top-hung |
| French window | 4 to 8 ft wide x about 7 ft high | Starts at floor level |
These are typical starting points, not fixed rules. Your architect’s drawing and the site measurement decide the final size.
How Much Window a Room Needs
A common rule of thumb, also reflected in Indian building guidelines, is that window openings should be at least about one-tenth of the floor area for daylight and fresh air. A 12 x 12 ft bedroom (144 sq ft) would then need roughly 15 sq ft or more of window, which a 4 x 4 ft window just covers. Rooms that face a narrow gap or the wall of the next building benefit from going larger than the minimum.
Sizes for Sliding and Casement Windows
Sliding windows. A two-shutter sliding window works well up to about 6 ft wide. Beyond that, three or four shutters keep each panel manageable, since very wide shutters get heavy on the rollers. If you want a mosquito mesh, plan a three-track frame; our post on single vs multi-track windows explains the layouts. You can also see Corinzo’s aluminium sliding windows.
Casement windows. Each opening sash is usually kept fairly narrow, often somewhere between 450 and 750 mm, so the hinges are not overloaded. Wider openings combine two sashes or add a fixed panel. Corinzo’s aluminium casement windows follow this approach.
Bathroom and Kitchen Windows
Bathroom windows are small because privacy and ventilation matter more than the view. A 600 x 450 mm or 600 x 600 mm opening is common, often with louvers or space for an exhaust fan. Our guide to the bathroom aluminium window with exhaust fan shows how the fan is fitted.
Kitchen windows sit above the counter, so the sill is usually higher than in other rooms, often around 3.5 ft from the floor depending on the counter and backsplash height. A wider, shorter window works well here.
Large and Special Sizes
Floor-to-ceiling windows, corner windows and French windows need stronger sections and usually toughened glass. If you are considering one, read our French window design ideas and see how fixed glass windows are used to divide large openings into manageable panels.
How to Measure a Window Opening
- Measure the width at the top, middle and bottom of the opening, and note the smallest figure.
- Measure the height on the left, centre and right, and again note the smallest.
- Check both diagonals. If they differ a lot, the opening is out of square and the fabricator needs to know.
- Leave a small clearance on each side for packing and sealant. Your fabricator will normally deduct this from the opening size.
- Measure after plastering is complete, not before.
For the full fitting process, see our step-by-step window installation guide.
Need help working out sizes for your project? Contact the Corinzo team.
Frequently Asked Questions (FAQs)
1. What is the standard size of an aluminium window?
There is no single standard. Common sizes are 4 x 4 ft for bedrooms, 3 x 3 ft for kitchens and 2 x 1.5 ft for bathrooms, all made to the measured opening.
2. What is the standard window height from the floor?
Windows usually sit on a sill about 2.5 to 3 ft (750 to 900 mm) high, with the top at around 7 ft (2100 mm).
3. What size is a bathroom window?
Usually around 600 x 450 mm or 600 x 600 mm, often with louvers or an opening for an exhaust fan.
4. How wide can a sliding window be?
A two-shutter sliding window works well up to about 6 ft. Wider openings are better split into three or four shutters.
5. What size is a 600×600 window in feet?
600 x 600 mm is roughly 2 x 2 ft, a common size for bathroom and utility ventilators.
6. How do I measure for a new window?
Measure the width and height at three points each, use the smallest figures, check the diagonals, and measure after plastering.