diff --git a/docs/COVERAGE.md b/docs/COVERAGE.md
new file mode 100644
index 0000000..ccd2e7b
--- /dev/null
+++ b/docs/COVERAGE.md
@@ -0,0 +1,33 @@
+# Coverage Prediction
+
+Meshview can display a predicted coverage boundary for a node. This is a **model**
+estimate, not a guarantee of real-world performance.
+
+## How it works
+
+The coverage boundary is computed using the Longley-Rice / ITM **area mode**
+propagation model. Area mode estimates average path loss over generic terrain
+and does not use a terrain profile. This means it captures general distance
+effects, but **does not** account for terrain shadows, buildings, or foliage.
+
+## What you are seeing
+
+The UI draws a **perimeter** (not a heatmap) that represents the furthest
+distance where predicted signal strength is above a threshold (default
+`-120 dBm`). The model is run radially from the node in multiple directions,
+and the last point above the threshold forms the outline.
+
+## Key parameters
+
+- **Frequency**: default `907 MHz`
+- **Transmit power**: default `20 dBm`
+- **Antenna heights**: default `5 m` (TX) and `1.5 m` (RX)
+- **Reliability**: default `0.5` (median)
+- **Terrain irregularity**: default `90 m` (average terrain)
+
+## Limitations
+
+- No terrain or building data is used (area mode only).
+- Results are sensitive to power, height, and threshold.
+- Environmental factors can cause large real-world deviations.
+
diff --git a/meshview/lang/en.json b/meshview/lang/en.json
index bff56f1..8b689fc 100644
--- a/meshview/lang/en.json
+++ b/meshview/lang/en.json
@@ -189,6 +189,9 @@
         "times_seen": "Times seen",
         "copy_import_url": "Copy Import URL",
         "show_qr_code": "Show QR Code",
+        "toggle_coverage": "Toggle Coverage",
+        "location_required": "Location required for coverage",
+        "coverage_help": "Coverage Help",
         "share_contact_qr": "Share Contact QR",
         "copy_url": "Copy URL",
         "copied": "Copied!",
diff --git a/meshview/lang/es.json b/meshview/lang/es.json
index 735b7a6..1a64cd2 100644
--- a/meshview/lang/es.json
+++ b/meshview/lang/es.json
@@ -175,6 +175,9 @@
     "times_seen": "Veces visto",
     "copy_import_url": "Copiar URL de importación",
     "show_qr_code": "Mostrar código QR",
+    "toggle_coverage": "Alternar cobertura",
+    "location_required": "Se requiere ubicación para la cobertura",
+    "coverage_help": "Ayuda de cobertura",
     "share_contact_qr": "Compartir contacto QR",
     "copy_url": "Copiar URL",
     "copied": "¡Copiado!",
diff --git a/meshview/radio/coverage.py b/meshview/radio/coverage.py
new file mode 100644
index 0000000..cc1c8a9
--- /dev/null
+++ b/meshview/radio/coverage.py
@@ -0,0 +1,136 @@
+import math
+from functools import lru_cache
+
+from pyitm import itm
+
+DEFAULT_CLIMATE = 5  # Continental temperate
+DEFAULT_GROUND = 0.005  # Average ground conductivity
+DEFAULT_EPS_DIELECT = 15.0
+DEFAULT_DELTA_H = 90.0
+DEFAULT_RELIABILITY = 0.5
+DEFAULT_MIN_DBM = -130.0
+DEFAULT_MAX_DBM = -80.0
+DEFAULT_THRESHOLD_DBM = -120.0
+EARTH_RADIUS_KM = 6371.0
+BEARING_STEP_DEG = 5
+
+
+def destination_point(
+    lat: float, lon: float, bearing_deg: float, distance_km: float
+) -> tuple[float, float]:
+    lat1 = math.radians(lat)
+    lon1 = math.radians(lon)
+    bearing = math.radians(bearing_deg)
+
+    d = distance_km / EARTH_RADIUS_KM
+
+    lat2 = math.asin(
+        math.sin(lat1) * math.cos(d) + math.cos(lat1) * math.sin(d) * math.cos(bearing)
+    )
+
+    lon2 = lon1 + math.atan2(
+        math.sin(bearing) * math.sin(d) * math.cos(lat1),
+        math.cos(d) - math.sin(lat1) * math.sin(lat2),
+    )
+
+    return math.degrees(lat2), math.degrees(lon2)
+
+
+@lru_cache(maxsize=512)
+def compute_coverage(
+    lat: float,
+    lon: float,
+    freq_mhz: float,
+    tx_dbm: float,
+    tx_height_m: float,
+    rx_height_m: float,
+    radius_km: float,
+    step_km: float,
+    reliability: float,
+) -> list[tuple[float, float, float]]:
+    points = []
+    distance = max(step_km, 1.0)
+    while distance <= radius_km:
+        for bearing in range(0, 360, BEARING_STEP_DEG):
+            rx_lat, rx_lon = destination_point(lat, lon, bearing, distance)
+            try:
+                loss_db, _ = itm.area(
+                    ModVar=2,  # Mobile: pctTime=reliability, pctConf=confidence
+                    deltaH=DEFAULT_DELTA_H,
+                    tht_m=tx_height_m,
+                    rht_m=rx_height_m,
+                    dist_km=distance,
+                    TSiteCriteria=0,
+                    RSiteCriteria=0,
+                    eps_dielect=DEFAULT_EPS_DIELECT,
+                    sgm_conductivity=DEFAULT_GROUND,
+                    eno_ns_surfref=301,
+                    frq_mhz=freq_mhz,
+                    radio_climate=DEFAULT_CLIMATE,
+                    pol=1,
+                    pctTime=reliability,
+                    pctLoc=0.5,
+                    pctConf=0.5,
+                )
+                rx_dbm = tx_dbm - loss_db
+                points.append((rx_lat, rx_lon, rx_dbm))
+            except itm.InputError:
+                continue
+        distance += step_km
+
+    return points
+
+
+@lru_cache(maxsize=512)
+def compute_perimeter(
+    lat: float,
+    lon: float,
+    freq_mhz: float,
+    tx_dbm: float,
+    tx_height_m: float,
+    rx_height_m: float,
+    radius_km: float,
+    step_km: float,
+    reliability: float,
+    threshold_dbm: float,
+) -> list[tuple[float, float]]:
+    perimeter = []
+    distance = max(step_km, 1.0)
+    for bearing in range(0, 360, BEARING_STEP_DEG):
+        last_point = None
+        last_rx_dbm = None
+        dist = distance
+        while dist <= radius_km:
+            try:
+                loss_db, _ = itm.area(
+                    ModVar=2,
+                    deltaH=DEFAULT_DELTA_H,
+                    tht_m=tx_height_m,
+                    rht_m=rx_height_m,
+                    dist_km=dist,
+                    TSiteCriteria=0,
+                    RSiteCriteria=0,
+                    eps_dielect=DEFAULT_EPS_DIELECT,
+                    sgm_conductivity=DEFAULT_GROUND,
+                    eno_ns_surfref=301,
+                    frq_mhz=freq_mhz,
+                    radio_climate=DEFAULT_CLIMATE,
+                    pol=1,
+                    pctTime=reliability,
+                    pctLoc=0.5,
+                    pctConf=0.5,
+                )
+            except itm.InputError:
+                dist += step_km
+                continue
+
+            rx_dbm = tx_dbm - loss_db
+            if rx_dbm >= threshold_dbm:
+                last_point = destination_point(lat, lon, bearing, dist)
+                last_rx_dbm = rx_dbm
+            dist += step_km
+
+        if last_point and last_rx_dbm is not None:
+            perimeter.append(last_point)
+
+    return perimeter
diff --git a/meshview/templates/node.html b/meshview/templates/node.html
index d20fe58..51b6793 100644
--- a/meshview/templates/node.html
+++ b/meshview/templates/node.html
@@ -338,6 +338,12 @@
         <button onclick="showQrCode()" id="showQrBtn">
             <span>🔳</span> <span data-translate-lang="show_qr_code">Show QR Code</span>
         </button>
+        <button onclick="toggleCoverage()" id="toggleCoverageBtn" disabled title="Location required for coverage">
+            <span>📡</span> <span data-translate-lang="toggle_coverage">Toggle Coverage</span>
+        </button>
+        <a class="inline-link" id="coverageHelpLink" href="/docs/COVERAGE.md" target="_blank" rel="noopener" data-translate-lang="coverage_help">
+            Coverage Help
+        </a>
     </div>
 
     <!-- Impersonation Warning -->
@@ -517,6 +523,7 @@
 
 <script src="https://cdn.jsdelivr.net/npm/echarts@5.5.0/dist/echarts.min.js"></script>
 <script src="https://cdnjs.cloudflare.com/ajax/libs/qrcodejs/1.0.0/qrcode.min.js"></script>
+<script src="https://unpkg.com/leaflet.heat/dist/leaflet-heat.js"></script>
 <script src="/static/portmaps.js"></script>
 
 <script>
@@ -635,6 +642,7 @@ let currentNode = null;
 let currentPacketRows = [];
 
 let map, markers = {};
+let coverageLayer = null;
 let chartData = {}, neighborData = { ids:[], names:[], snrs:[] };
 
 let fromNodeId = new URLSearchParams(window.location.search).get("from_node_id");
@@ -708,6 +716,20 @@ async function loadNodeInfo(){
             node.last_lat ? (node.last_lat / 1e7).toFixed(6) : "—";
         document.getElementById("info-lon").textContent =
             node.last_long ? (node.last_long / 1e7).toFixed(6) : "—";
+        const coverageBtn = document.getElementById("toggleCoverageBtn");
+        const coverageHelp = document.getElementById("coverageHelpLink");
+        if (coverageBtn) {
+            const hasLocation = Boolean(node.last_lat && node.last_long);
+            coverageBtn.disabled = !hasLocation;
+            coverageBtn.title = hasLocation
+                ? ""
+                : (nodeTranslations.location_required || "Location required for coverage");
+            coverageBtn.style.display = hasLocation ? "" : "none";
+        }
+        if (coverageHelp) {
+            const hasLocation = Boolean(node.last_lat && node.last_long);
+            coverageHelp.style.display = hasLocation ? "" : "none";
+        }
 
         let lastSeen = "—";
         if (node.last_seen_us) {
@@ -799,6 +821,43 @@ function initMap(){
     }).addTo(map);
 }
 
+async function toggleCoverage() {
+    if (!map) initMap();
+
+    if (coverageLayer) {
+        map.removeLayer(coverageLayer);
+        coverageLayer = null;
+        return;
+    }
+
+    const nodeId = currentNode?.node_id || fromNodeId;
+    if (!nodeId) return;
+
+    try {
+        const res = await fetch(`/api/coverage/${encodeURIComponent(nodeId)}?mode=perimeter`);
+        if (!res.ok) {
+            console.error("Coverage request failed", res.status);
+            return;
+        }
+        const data = await res.json();
+        if (!data.perimeter || data.perimeter.length < 3) {
+            console.warn("Coverage perimeter missing or too small");
+            return;
+        }
+        coverageLayer = L.polygon(data.perimeter, {
+            color: "#6f42c1",
+            weight: 2,
+            opacity: 0.7,
+            fillColor: "#000000",
+            fillOpacity: 0.10
+        }).addTo(map);
+        map.fitBounds(coverageLayer.getBounds(), { padding: [20, 20] });
+        map.invalidateSize();
+    } catch (err) {
+        console.error("Coverage request failed", err);
+    }
+}
+
 function hideMap(){
     const mapDiv = document.getElementById("map");
     if (mapDiv) {
diff --git a/meshview/web.py b/meshview/web.py
index a050474..b723e64 100644
--- a/meshview/web.py
+++ b/meshview/web.py
@@ -229,6 +229,20 @@ async def serve_page(request):
     return web.Response(text=content, content_type="text/html")
 
 
+@routes.get("/docs/{doc}")
+async def serve_doc(request):
+    """Serve documentation files from docs/ (markdown)."""
+    doc = request.match_info["doc"]
+    docs_root = pathlib.Path(__file__).parent.parent / "docs"
+    doc_path = (docs_root / doc).resolve()
+
+    if not doc_path.is_file() or docs_root not in doc_path.parents:
+        raise web.HTTPNotFound(text="Document not found")
+
+    content = doc_path.read_text(encoding="utf-8")
+    return web.Response(text=content, content_type="text/markdown")
+
+
 @routes.get("/net")
 async def net(request):
     return web.Response(
diff --git a/meshview/web_api/api.py b/meshview/web_api/api.py
index 3a59ddc..34a963a 100644
--- a/meshview/web_api/api.py
+++ b/meshview/web_api/api.py
@@ -6,7 +6,7 @@ import logging
 import os
 
 from aiohttp import web
-from sqlalchemy import func, select, text
+from sqlalchemy import func, select
 
 from meshtastic.protobuf.portnums_pb2 import PortNum
 from meshview import database, decode_payload, store
@@ -15,6 +15,14 @@ from meshview.config import CONFIG
 from meshview.models import Node, NodePublicKey
 from meshview.models import Packet as PacketModel
 from meshview.models import PacketSeen as PacketSeenModel
+from meshview.radio.coverage import (
+    DEFAULT_MAX_DBM,
+    DEFAULT_MIN_DBM,
+    DEFAULT_RELIABILITY,
+    DEFAULT_THRESHOLD_DBM,
+    compute_coverage,
+    compute_perimeter,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -636,9 +644,7 @@ async def health_check(request):
     # Check database connectivity
     try:
         async with database.async_session() as session:
-            result = await session.execute(
-                select(func.max(PacketModel.import_time_us))
-            )
+            result = await session.execute(select(func.max(PacketModel.import_time_us)))
             last_import_time_us = result.scalar()
         health_status["database"] = "connected"
         if last_import_time_us is not None:
@@ -1035,3 +1041,83 @@ async def api_node_impersonation_check(request):
     except Exception as e:
         logger.error(f"Error checking impersonation for node {node_id}: {e}")
         return web.json_response({"error": "Failed to check impersonation"}, status=500)
+
+
+@routes.get("/api/coverage/{node_id}")
+async def api_coverage(request):
+    try:
+        node_id = int(request.match_info["node_id"], 0)
+    except (KeyError, ValueError):
+        return web.json_response({"error": "Invalid node_id"}, status=400)
+
+    def parse_float(name, default):
+        value = request.query.get(name)
+        if value is None:
+            return default
+        try:
+            return float(value)
+        except ValueError as exc:
+            raise web.HTTPBadRequest(
+                text=json.dumps({"error": f"{name} must be a number"}),
+                content_type="application/json",
+            ) from exc
+
+    try:
+        freq_mhz = parse_float("freq_mhz", 907.0)
+        tx_dbm = parse_float("tx_dbm", 20.0)
+        tx_height_m = parse_float("tx_height_m", 5.0)
+        rx_height_m = parse_float("rx_height_m", 1.5)
+        radius_km = parse_float("radius_km", 40.0)
+        step_km = parse_float("step_km", 0.25)
+        reliability = parse_float("reliability", DEFAULT_RELIABILITY)
+        threshold_dbm = parse_float("threshold_dbm", DEFAULT_THRESHOLD_DBM)
+    except web.HTTPBadRequest as exc:
+        raise exc
+
+    node = await store.get_node(node_id)
+    if not node or not node.last_lat or not node.last_long:
+        return web.json_response({"error": "Node not found or missing location"}, status=404)
+
+    lat = node.last_lat * 1e-7
+    lon = node.last_long * 1e-7
+
+    mode = request.query.get("mode", "perimeter")
+    if mode == "perimeter":
+        perimeter = compute_perimeter(
+            lat=round(lat, 7),
+            lon=round(lon, 7),
+            freq_mhz=round(freq_mhz, 3),
+            tx_dbm=round(tx_dbm, 2),
+            tx_height_m=round(tx_height_m, 2),
+            rx_height_m=round(rx_height_m, 2),
+            radius_km=round(radius_km, 2),
+            step_km=round(step_km, 3),
+            reliability=round(reliability, 3),
+            threshold_dbm=round(threshold_dbm, 1),
+        )
+        return web.json_response(
+            {"mode": "perimeter", "threshold_dbm": threshold_dbm, "perimeter": perimeter}
+        )
+
+    points = compute_coverage(
+        lat=round(lat, 7),
+        lon=round(lon, 7),
+        freq_mhz=round(freq_mhz, 3),
+        tx_dbm=round(tx_dbm, 2),
+        tx_height_m=round(tx_height_m, 2),
+        rx_height_m=round(rx_height_m, 2),
+        radius_km=round(radius_km, 2),
+        step_km=round(step_km, 3),
+        reliability=round(reliability, 3),
+    )
+
+    min_dbm = DEFAULT_MIN_DBM
+    max_dbm = DEFAULT_MAX_DBM
+    if points:
+        vals = [p[2] for p in points]
+        min_dbm = min(min_dbm, min(vals))
+        max_dbm = max(max_dbm, max(vals))
+
+    return web.json_response(
+        {"mode": "heatmap", "min_dbm": min_dbm, "max_dbm": max_dbm, "points": points}
+    )
diff --git a/requirements.txt b/requirements.txt
index 5265cb5..9e21e48 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,6 +24,7 @@ MarkupSafe~=3.0.2
 
 # Graphs / diagrams
 pydot~=3.0.4
+pyitm~=0.3
 
 
 #############################
@@ -47,4 +48,4 @@ objgraph~=3.6.2
 # Testing
 pytest~=8.3.4
 pytest-aiohttp~=1.0.5
-pytest-asyncio~=0.24.0
\ No newline at end of file
+pytest-asyncio~=0.24.0