How to Level and Measure Accurately Before You Fix Anything
Practical marking-out methods for shelves, frames and brackets, including spirit levels, laser lines, spacing, centring and avoiding wonky results.
Level and accurate fixings are the difference between a neat finish and a job that looks off every time you walk past. Most wonky shelves and uneven frames are not the fault of the fixing, but of poor marking out. The good news is that careful measuring is quick and requires very little equipment.
The basic kit
- Tape measure: a steel one, with a locking feature.
- Spirit level: the longer, the more reliable. A 60 cm level is a good all-rounder.
- Pencil: sharp, and a rubber to remove marks.
- Masking tape: to hold templates or mark heights.
- Laser line level (optional): helpful for long runs or several shelves.
- Square: for checking right angles.
Level versus plumb versus true
- Level: horizontal. Shelves, rails and TV brackets usually follow this.
- Plumb: vertical. Tall units and curtain tracks follow this.
- Square to the room: sometimes the wall or ceiling is not level, so aligning with the room's features looks wrong even if it is correct. Check how your item sits against the ceiling, window and furniture.
In older homes, floors, ceilings and walls are rarely perfectly level. Decide which line your eye will follow and aim for that.
Marking out step by step
- Decide the height from the floor or a feature, and mark it at both ends of the proposed line.
- Use the level to join the two marks, or hold it against the wall and draw along it.
- Check the level by flipping it end for end. If the bubble reads differently, it needs adjusting or replacing.
- Measure fixing points from the line, not from the ceiling or floor.
- Double-check measurements before drilling.
Centring and spacing
For items placed above furniture or between windows:
- Measure the full width of the space, then half of it, and mark the centre.
- Measure the item's width, halve it, and mark the ends from the centre.
- For several items, add the widths and gaps, subtract from the space, and divide the remainder to get equal margins.
When hanging multiple shelves or frames, use a story stick: a piece of wood with marks, to repeat the same measurement quickly. How to plan a gallery wall shows how to keep groups of frames consistent.
Marking fixing holes
Use the item itself or its template where possible. For two-point fixings, level the item on the wall and mark through the holes. For brackets, mark both fixings at the same height using the level.
Where the item has uneven hole spacing, measure from one side and work across, checking against the item.
Deal with uneven walls
- Slightly bowed walls can create a gap behind shelves. A thin packer or filler may be needed.
- On very uneven walls, a batten fixed first and then levelled with packers gives a flat base.
- Use fixing positions on the high spots first, then pack the low ones.
Fix only after checking services
Before drilling, scan for pipes and cables; how to find studs, pipes and cables before drilling explains what to look for. Often the best level line will need to move a little to avoid services.
Mistakes to avoid
- Trusting a short or cheap level.
- Marking with a thick pencil, which ruins accuracy.
- Measuring from the ceiling or floor when they are not level.
- Forgetting the thickness of the item when measuring offsets.
A worked example: three frames in a row
You want three frames at the same height over a sofa. Measure the sofa width, then centre the group on it. Mark a horizontal reference line with a level, and a vertical centre. Hang each frame from the line so the hooks match, rather than from the frame tops. Check each one with a small level, then mark the fixing positions with pencil and double-check measurements before drilling.
Quick tools comparison
| Tool | Good for | Limitations |
|---|---|---|
| Spirit level | General levelling | Accuracy depends on length |
| Laser level | Long runs, rows | Needs a visible line, batteries |
| Tape measure | Spacing | Can slip or bend |
| Plumb line | Vertical marks | Needs time to settle |
| Phone level app | Quick checks | Less precise |
Common errors
- Measuring from the ceiling or floor, which may not be level.
- Misreading a tape from the inside of the hook.
- Marking holes on the wall from an old hole position.
- Forgetting the thickness of brackets in your height calculation.
- Letting the pencil mark drift with the tool.
Checking before you drill
When you are sure about the positions, check again for services behind the wall, then make small pilot marks. Use painter's tape to hold templates, and step back to look. See how to plan a gallery wall for layouts with several frames.
Frequently asked questions
Is a laser level worth it?
For several shelves or a long line, yes, as it projects a line across the whole wall. For a single picture, a normal level is fine.
What if the ceiling is not level?
Do not follow the ceiling for shelves or pictures unless the item is meant to align with it. Use a spirit level and decide on the line visually.
How do I check my spirit level is accurate?
Place it on a flat surface, note the bubble, then turn it end for end. If it reads the same both ways, it is accurate.