Even Spacing Calculator
Enter the length of a run and the width of each item, and choose a set number of items or a largest gap, to get the equal gap, the center-to-center distance and every mark measured from the start of the run, for shelves, hooks and cleats.
Estimates for planning, not professional advice. Read the full notice.
Example: five shelf brackets on a rail
5 items placed
- Gap between items and at the ends 7.083 in
- Center to center 10.583 in
- First item, left edge 7.083 in
- First item, center 8.833 in
Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.
Your project
Enter a size to see your total.
Each product is rounded up once for the whole project, so the total can be less than the items bought alone added together. A line counted from a cut layout (sheets, boards or tiles laid out piece by piece) is counted for each item and added.
Gaps and marks
These numbers follow the sizes above for every item in the list. Every mark is measured from the start of the run.
Shopping list
| Item | Size | Buy |
|---|---|---|
| Items to place | items placed | 5 |
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Worked example: five shelf brackets on a rail
Show the working
- Width the items take 5 items × 3.5 in = 17.5 in
- Run left for gaps 60 in − 17.5 in = 42.5 in
- Gap: one more gap than items, so the run ends in a gap 42.5 in ÷ 6 gaps = 7.083 in
- First center: the gap plus half an item 7.083 in + 1.75 in = 8.833 in
Assumptions
The figures behind the example. Sourced figures link to their source below; a default is a starting value to check against your label or supplier.
| Assumption | Value | Details and changes |
|---|
Feet and inches, like 12' 6"
The same job under the three end rules
Gap, first center and center-to-center distance for the example run under each end rule
| End rule | Gap | First center | Center to center |
|---|---|---|---|
| Gaps at both ends | 7.083 in | 8.833 in | 10.583 in |
| Flush to both ends | 10.625 in | 1.75 in | 14.125 in |
| Flush at the start only | 8.5 in | 1.75 in | 12 in |
Only the end rule changes. A gap at both ends has one more gap than items; flush to both ends has one fewer; flush at the start only has the same number.
Marks for the example run
Left edge, center and right edge of each item, measured from the start of the example run
| Item | Left edge | Center | Right edge |
|---|---|---|---|
| Item 1 | 7.083 in | 8.833 in | 10.583 in |
| Item 2 | 17.667 in | 19.417 in | 21.167 in |
| Item 3 | 28.25 in | 30 in | 31.75 in |
| Item 4 | 38.833 in | 40.583 in | 42.333 in |
| Item 5 | 49.417 in | 51.167 in | 52.917 in |
Every mark is measured from the start of the run, never from the mark before it, so a slip does not carry along.
Questions
What is the difference between a gap at the ends and flush ends?
With a gap at both ends the first and last items sit one gap in from the run's ends. Flush to both ends puts them against the ends, and flush at the start only puts the first against the start. The first table shows all three for one job.
What is the difference between the gap and the distance on center?
The gap is the clear space between two items. Center to center is the gap plus the width of one item. For hooks with no width the two are the same.
How do I space shelves or coat hooks evenly?
Enter the length of the run and the item width, leave the width empty for hooks, choose the number of items, and mark each center from the start of the run.