Calculator inputs
Enter approximate dimensions and conditions. For long corridors, consider adding one extra node per 25–35 meters.
Example data
A sample scenario showing how the estimate scales with obstacles and floor area.
| Length (m) | Width (m) | Floors | Radius (m) | Material | Walls | Overlap | Repeaters |
|---|---|---|---|---|---|---|---|
| 60 | 25 | 2 | 14 | Concrete | 2 | 20% | 35 |
Formula used
This calculator estimates coverage using an adjusted service area per device:
The model is a planning estimate. Real layouts, antenna placement, and interference can shift results. Use a quick site survey to validate.
How to use this calculator
- Measure building length, width, and count usable floors.
- Enter your router’s approximate indoor radius from its spec or experience.
- Select wall material and estimate how many walls separate likely node locations.
- Pick an overlap target; 15–25% is typical for roaming.
- Click Calculate, then use spacing tips for rough placement.
- Validate with a walk test; adjust nodes for dead zones.
Coverage requirements in building fit-outs
Repeaters are often planned during interior buildouts, before final furniture and partitions. For open workshops, start with a router radius of 14–18 m. For office grids, 10–14 m is safer. Ceiling height also matters; high bays can create shadowing behind racks. Use this calculator to convert rough drawings into an initial device count and spacing for procurement.
Effective radius and backhaul impact
A repeater rarely matches the router’s reach because it shares airtime for backhaul. The efficiency factor represents that loss. Values around 0.70–0.80 are common for single-band repeating, especially on channels. Dedicated backhaul radios, mesh systems, or wired uplinks can justify 0.85–0.95. If you expect heavy streaming, cameras, or VOIP, keep the factor conservative to avoid optimistic counts.
Wall materials and obstacle allowance
Signals drop sharply through dense materials. Light partitions and glass usually behave better than masonry, while reinforced concrete and metal cladding are most challenging. For planning, each additional wall multiplies loss, so two concrete walls may reduce usable area to nearly one third. Stairwells, lift shafts, and fire doors often behave like extra walls. If your floor has metal racks or machinery bays, assume extra loss and plan one spare node.
Overlap targets for roaming and reliability
Overlap improves handoff and reduces dead zones, but it also increases node count. A 15–25% overlap works for most offices, while warehouses may operate at 10–15%. For classrooms or meeting suites, aim closer to 25% to reduce edge drops. High overlap above 40% is typically reserved for voice, scanning, or moving equipment that cannot tolerate brief disconnects.
Installation checks and adjustment steps
Use the suggested spacing as a starting grid, then verify with a walk test. Place repeaters where they can “see” the router or previous node with good signal, ideally above head height and away from metal. After installation, measure throughput in key rooms at work hours, adjust channels if you control them, and relocate nodes away from electrical panels or thick cores.
FAQs
Does this calculator replace a site survey?
No. It provides a planning estimate from dimensions and obstacles. A quick walk test with a phone or analyzer should confirm dead zones, interference, and real device placement before purchase.
What router radius should I enter?
Use a conservative indoor figure from experience or specifications. Typical ranges are 8–18 m. If the space has dense walls, shelving, or machinery, choose the lower end.
Why does overlap increase the repeater count?
Overlap reserves extra shared coverage so devices can roam without dropping. More overlap reduces the effective service area per node, so you need more nodes to cover the same floor area.
How do floors affect the result?
The calculator multiplies area by floor count to reflect additional coverage demand. If floors are open atriums or share strong vertical signal paths, you may need fewer than the estimate.
How should I interpret wall count?
Enter the average number of significant walls between the router and repeater locations. For open halls use 0–1. For typical offices use 2–3. Increase it for cores, fire doors, or stairwells.
When should I add extra repeaters?
Add one spare node for high-risk areas: concrete cores, metal shelving, long corridors, or critical rooms. Also add capacity if many users stream, run cameras, or use voice tools.