We measure every door ourselves at the free survey — you don't need to. But if you're early in the buying process and want a rough quote, three measurements will do it.
Use a steel tape measure (not fabric). Measure in millimetres. Take each measurement in three places — top, middle, bottom for width; left, middle, right for height — and write down the smallest.
1. Width
Measure the brickwork-to-brickwork width of the opening — not the existing door, and not the frame. Take the measurement at three heights and write down the smallest.
Typical UK front doors fall into one of these standard widths: 762mm (2'6"), 838mm (2'9"), 914mm (3'0"), or 920mm.
2. Height
Measure from the floor (or threshold) to the top of the brickwork — the very top of the opening, not the existing frame. Again, take the measurement in three places (left, middle, right) and write down the smallest.
Most UK front doors are 1981mm (6'6"), 2032mm (6'8"), or 2057mm (6'9").
3. Wall thickness
Open the existing door and measure the depth of the reveal — i.e. the distance from the outside face of the brickwork to the inside face. This tells us the frame depth you'll need.
Other things to check
- Threshold height — is the existing door flush, low-threshold, or stepped?
- Handing — does the door open inwards or outwards, and which way does the handle sit?
- Hinge side — which side of the opening do the hinges sit on?
- Cill — is there an internal sill we'll need to work around?
- Letterbox — is the existing letterbox position important to keep?
All of this is what we do at the free survey, and we'll spot things you wouldn't (out-of-square openings, bowed brickwork, knackered cills). Your measurement gives you a budget figure; ours is what gets manufactured.
Common mistakes
- Measuring the existing door, not the opening.
- Measuring once. Brickwork rarely opens square — always take three readings and use the smallest.
- Using inches when the supplier wants millimetres (and vice versa).
- Forgetting to allow for the threshold or cill.
Frequently asked
Do I need to measure the door myself?+
Not really — the survey is free, takes 20 minutes, and ours is the measurement we manufacture from. A rough self-measure is useful for getting a budget quote, but it's not required.
What if my opening isn't a standard size?+
Almost all of our doors are manufactured to your exact measurements — we don't pull from stock. Non-standard sizes are normal; price stays the same.