WiFi Signal SimulatorSimulate floor plan WiFi coverage and router placement online

1Design Layout 2Place APs 3Save 4Simulate
Floor
Click to draw continuous walls, hold Shift for orthogonal lock, snaps to vertices automatically; Esc to cancel, Del to delete; hold Space / middle-button to pan, scroll to zoom
Your browser does not support HTML5 Canvas, so the WiFi coverage heatmap cannot be displayed. Please use a recent version of Chrome, Edge, Firefox or Safari.
💡 First Time? 3 Ways to Get Started

Draw your layout, place routers, and inspect whole-home WiFi signal in seconds

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🏠 Load Sample Layout Recommended
2-Bedroom layout loaded in 1 click. Zero effort to see the heatmap instantly.
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🗺️ Trace a Floor Plan Photo
Upload a blueprint image as a semi-transparent background and trace walls directly.
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✏️ Draw from Scratch
Click start point → move and click corners (Shift to straighten) → right-click to finish.
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💡 Open Full Visual Tutorial

A free online WiFi coverage simulator for any floor plan

Free online WiFi coverage simulator: draw your floor plan, place routers and see where signal drops. Models wall loss, multi-floor homes and mesh placement.

How WiFi coverage is calculated: the ITU-R P.1238 indoor model

Draw your floor plan wall by wall, choosing materials (wood, brick, concrete) and marking load-bearing walls. Place WiFi access points anywhere on the canvas. The engine flood-fills indoor space from the canvas boundary, then computes received signal strength (RSSI in dBm) for every sample point with the ITU-R P.1238 indoor model: free-space path loss plus per-material penetration loss (wood ≈ 3 dB, brick ≈ 7 dB, concrete ≈ 12 dB at 2.4 GHz, higher at 5 GHz), adjusted for oblique penetration and softened at corners to model diffraction. Add as many floors as you need for a villa or duplex: each floor carries its own walls, storey height and slab material, and access points on other floors still contribute to the current floor — through the slab (≈ 18 dB for concrete) or straight up through a void opening such as a stairwell or double-height living room, where only 1.5 dB of edge diffraction applies. The result is a continuous heatmap where green means strong and red means weak, with anything below -95 dBm treated as a dead zone.

Use cases: new-home planning, mesh node selection, multi-storey layouts

Planning router positions before moving into a new home · comparing mesh node placement · explaining dead zones on a shared floor plan · teaching how wall materials affect wireless signal. Everything happens locally in your browser; nothing is uploaded.

Getting started in 3 steps: from blank canvas to whole-home signal map

  1. Draw the floor plan. Trace each wall, pick its material (wood / brick / concrete) and tick load-bearing walls. Made a mistake? Ctrl+Z undoes any step.
  2. Place access points. Click where you would put a router and drag to fine-tune. For villas, use “+ Add floor” and lay out each storey.
  3. Read the result. Run the simulation for a heatmap: green is strong, red is weak, and the dashed -65 dBm contour marks the usability boundary. Drag APs around to compare and pick the layout with the fewest dead zones.

WiFi Coverage Planning Guides

Every guide gives reproducible dB figures you can verify against your own floor plan.

Best Router Placement: 4 Common Spots Compared
Living room, media cabinet or the wiring box? Compare four router positions with the ITU-R P
2.4GHz vs 5GHz WiFi: Which Band Should You Use?
How much do 2.4GHz and 5GHz really differ? Compare wall loss and coverage radius under one m
Does a Load-Bearing Wall Block WiFi? dB Loss Chart
What do wood, glass, brick and reinforced concrete cost in dB? A 2.4/5GHz wall loss chart, p
Mesh Node Placement: How Far Apart Should They Be?
How far apart should mesh nodes sit and how many do you need? A calculable spacing standard
Duplex and Villa WiFi: Planning Multi-Storey Coverage
What an 18 dB concrete slab really costs, why a stairwell void beats it by 16 dB, and how ma
WiFi Signal Strength dBm Chart: Is −70 dBm Good?
What RSSI counts as normal? A dBm banding chart, why signal bars are unreliable, and how to
Wi-Fi 7 and 6GHz Wall Attenuation: Is a 6GHz Router Worth It?
Does Wi-Fi 7 6GHz penetrate walls? We compare 2.4G, 5G and 6GHz attenuation with ITU-R P.123
Whole-Home FTTR vs AC+AP: Placement and Heat Management Guide
Should you pick FTTR or PoE AC+AP? Why do in-wall panel APs overheat, how does mounting heig
2026 Singles' Day Whole-Home WiFi Guide: Pitfalls & Router Picks
Don't just chase discounts on Singles' Day: weak-box placement, single-router large homes, b

FAQ

How accurate is the WiFi signal simulation?
It estimates received signal strength (RSSI in dBm) with the ITU-R P.1238 indoor propagation model: free-space path loss plus per-material penetration loss (wood ≈ 3 dB, brick ≈ 7 dB, concrete ≈ 12 dB at 2.4 GHz, higher at 5 GHz), with oblique penetration and corner diffraction taken into account. It is designed for comparing router placements, not for replacing professional RF survey tools.
Does a load-bearing wall block WiFi?
Yes. Load-bearing walls are usually reinforced concrete, which attenuates wireless signal heavily — about 17 dB per pass at 2.4 GHz and around 25 dB at 5 GHz. Switch the band selector to see how much faster 5 GHz decays through walls.
Where should I place my router?
Place APs near the centre of the area you want covered, keep paths to key rooms clear of multiple walls, and avoid routing through concrete or load-bearing walls. Drag an AP while simulating to watch the heatmap update in real time; load the sample layout to see a typical two-AP setup.
Can it simulate a multi-storey house or duplex?
Yes. Add as many floors as you need and switch between them with the floor tabs. Each floor keeps its own walls, storey height and slab material, and APs on other floors contribute to the floor you are viewing — through the slab, or straight up through a void opening such as a stairwell or a double-height living room, which you draw with the Void Opening tool.
Is this tool free? Do I need to install anything?
It runs entirely in your browser for free — no install, no account, no upload. Your floor plan never leaves your device.
How do I simulate whole-home WiFi wall attenuation?
Draw your walls and pick materials (wood / brick / concrete), place 1–2 access points in the rooms you use most, then run the simulation. Count wall crossings: at 2.4 GHz each brick wall costs about 7 dB and concrete about 12 dB — after two walls you are usually below -80 dBm. That is the core of whole-home WiFi wall attenuation simulation: measure before you buy, so you do not pick the wrong router.
How can I test mesh router placement?
Put the main router near the centre of your home, then drag mesh nodes close to the -65 dBm contour line (shown by default), keeping each node's backhaul path through at most one wall. The heatmap updates live as you drag, so you can balance coverage against backhaul quality — the fastest way to test mesh router placement, far quicker than trial-and-error with real hardware.
What is the difference between 2.4G and 5G coverage heatmaps?
Toggle the band selector to generate each: 2.4G penetrates walls better and covers more area, good as the baseline for wall-heavy layouts; 5G is faster but loses about 25 dB through a single concrete wall, best for open living rooms. Comparing the 2.4G and 5G coverage heatmaps side by side tells you which band each room should use, or whether you need a mesh node to fill 5G dead zones.

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