Walkie-Talkie Range: What Actually Decides Coverage

Why the number on the box is not a site result

Every radio datasheet has a range figure, and almost every figure is measured under conditions that do not exist on your site. The test usually assumes clear line of sight, no buildings, no interference, an ideal antenna height and sometimes a lower power setting or a different antenna from the one in the box.

On a real site, the signal has to pass through walls, floors, racking, vehicles and people. It has to compete with electrical noise, other radios and the general congestion of the band. The result is that a radio advertised at “5 miles” may cover one floor of a hotel, and a radio advertised at “2 miles” may cover a whole open yard.

The useful planning question is not “what is the range?” but “what path does the signal need to take, and what is between the two antennas?” That is a coverage design question, and it can be answered with a site survey.

The four factors that decide range

Four factors explain most of the difference between the datasheet and the site:

Antenna height. Height above the clutter is the single biggest lever. A handheld at 1.5 m and a repeater antenna at 30 m do not have the same path.
Obstructions. Concrete, steel, metal racking, foil-backed insulation, lifts and basements absorb or reflect the signal. Each wall and floor adds loss.
Power and antenna gain. Doubling power adds about 3 dB; a higher-gain antenna can add more, but only in the direction it is pointed, and cable loss can cancel the gain.
Noise and interference. A weak signal in a quiet band can be readable; the same signal in a noisy electrical environment may not be. Digital systems also have a cliff: below a certain signal-to-noise ratio, the audio disappears.

Terrain matters outdoors: a hill, a building or a line of trees between the antennas can block the path even when the distance is short. Over water or flat open ground, VHF often travels further than UHF; inside a building, UHF usually behaves better because it penetrates and reflects around obstacles more predictably.

What range can you expect outdoors?

Use these figures as planning estimates, not guarantees:

Scenario	Typical handheld-to-handheld range	What changes it
Open field, clear line of sight	3–5 km	Antenna height, terrain, power
Suburban street, low buildings	1–3 km	Building density, trees, vehicle traffic
Dense urban street	0.5–1.5 km	Buildings, multipath, noise
Inside a warehouse	100–300 m, often less across racking	Racking, stock, metal cladding
Inside a concrete building	One floor or one corridor	Walls, floors, stair cores
Handheld to a repeater on a high site	5–15 km	Repeater antenna height, path, handheld power

If the requirement is “the whole site”, the handheld-to-handheld number is not the one that matters. The design usually needs a repeater on a high antenna, with handhelds close enough to reach it.

What happens to range inside a building?

Inside a building, the path loss is dominated by walls, floors and the materials in them. A concrete wall with rebar can cost 10–20 dB or more; a metal-framed wall, a lift shaft or a basement slab can cost more. A handheld that works in the lobby may fail in the stair core, the plant room or the car park.

The areas that fail first are predictable:

basements and plant rooms;
stair cores and service corridors;
car parks and loading docks;
long corridors with several fire doors;
warehouses with tall racking and metal stock.

A single repeater on the roof can cover the upper floors and the open areas, but it rarely reaches a deep basement. The usual fix is an indoor antenna system — a small distributed antenna network fed by the repeater — or a second site closer to the problem area.

For a hotel-specific example, see hotel two-way radios. For a warehouse, see warehouse communications.

When does a repeater actually help?

A repeater helps when it can hear the handheld and the handheld can hear the repeater. It does not create coverage where neither path exists. The three conditions are:

The repeater antenna is above the clutter. A rooftop or mast position is usually better than a repeater in the basement.
The handheld can reach the repeater. If the user is deep in a basement, the repeater on the roof may not hear them.
The duplex pair and isolation are correct. A repeater needs a frequency pair and enough isolation between the transmit and receive antennas; otherwise it desenses itself and the coverage collapses.

A repeater also adds capacity. On DMR, one 12.5 kHz carrier carries two TDMA time slots, so two talk groups can share one frequency. On analog, one repeater channel carries one conversation at a time. The capacity question is separate from the coverage question, but both decide whether the system works.

How do you plan coverage floor by floor?

A practical indoor plan starts with a walk-through, not a drawing:

Mark the areas that matter. Guest floors, service corridors, basements, plant rooms, car parks, loading docks.
Walk the path with a test set. Record where the signal drops and where audio becomes unreadable.
Choose the architecture. Direct mode, one repeater, repeater plus indoor antennas, or multiple sites.
Place the antennas. In an indoor system, antenna positions are chosen for even coverage, not maximum signal in one corridor.
Check the edges. Stair cores, lift lobbies, fire doors and the perimeter are the usual failure points.
Plan the channels and talk groups. Coverage without a usable group plan still fails the operation.

The coverage planner turns the first four questions into a starting recommendation. It is a screening tool, not a substitute for a site survey.

How do you test coverage before acceptance?

Agree the test method before installation. A defensible acceptance test includes:

a grid or route with defined test points;
signal level and audio quality recorded at each point;
talk-out and talk-in tested separately;
the final programming and final antenna positions used;
pass/fail thresholds agreed in writing;
a baseline record kept for future changes.

For a large site, a drive test covers the outdoor routes and a walk test covers the indoor areas. For a multi-floor building, test each floor and the stair core. For a repeater, test the handheld-to-repeater path and the repeater-to-handheld path separately, because they can fail for different reasons.

When is PoC the better answer?

PoC (push-to-talk over cellular) is better when the coverage problem is distance or geography rather than a single building. It uses the mobile network, so it works across a city or a country without a radio site, and it can be deployed in days.

The trade-offs are:

it depends on mobile coverage, which is weak in basements, tunnels and remote areas;
it adds a subscription per user and a platform cost;
it has higher latency than conventional radio;
it needs SIM management, device management and a data plan.

For a single critical site with no mobile coverage, a conventional repeater or a direct-mode system is usually more reliable. For a multi-city fleet or a temporary event, PoC can be the practical choice. The analog vs DMR vs PoC guide compares the three technologies side by side.

If you want a first-pass answer for your building, start with the coverage planner, then send the site details through the contact page for a design review.

Frequently asked questions

Click a question to see the answer

What range can I realistically expect from a handheld radio?

There is no single number. Handheld to handheld outdoors in open or suburban terrain, expect roughly 1–3 km, and up to about 5 km with clear line of sight. Indoors, expect one floor or one corridor in a concrete building. With a repeater on a high antenna, a handheld can work several kilometres across a site, but the handheld-to-repeater path is the limit.

What is a radio repeater, and how much range does it add?

A radio repeater receives a signal on one frequency and retransmits it on another from a high antenna, so handhelds do not have to reach each other directly. That can turn a 1–3 km handheld-to-handheld path into several kilometres of site coverage, but the useful range in miles depends on antenna height, cable loss and the handheld-to-repeater path. A repeater radio does not create coverage where there is no path to the antenna, and it needs a duplex frequency pair.

Why does the box say 5 miles but the radio fails in the next room?

The box number is a laboratory or open-field figure measured with clear line of sight, no buildings, no interference and often at reduced power or with an ideal antenna. Once walls, floors, racking and bodies are in the path, the signal loses far more energy than the open-field test assumes. Treat the box number as an upper bound, not a site prediction.

Do I need a repeater for a single building?

Not always. A small open-plan site can work handheld-to-handheld. A repeater becomes necessary when users are spread across floors, basements and long corridors, when one talk group must hear everyone, or when coverage has to leave the building. A site survey or the coverage planner gives a first-pass answer.

What is the difference between simplex and duplex?

Simplex uses one frequency: radios take turns transmitting and receiving. Duplex uses two frequencies — a repeater receives on one and transmits on the other — so users can talk at the same time and the repeater extends coverage. A repeater installation needs a duplex pair and a duplexer tuned to the spacing in the licence.

Does higher power always give more range?

No. Power helps at the margin, but antenna height, antenna gain, cable loss, the receiver’s sensitivity and the path between the antennas usually matter more. Doubling power adds about 3 dB, which is a modest improvement; raising the antenna above the clutter can add far more. Increasing power also increases interference and battery drain.

How do I prove coverage after installation?

Agree the test method and pass/fail thresholds in writing before work starts. Then walk and drive the site with the final programming and final antenna positions, log signal level and audio quality at defined points, test talk-out and talk-in separately, and keep the result as a baseline for future changes.

When is PoC a better answer than a repeater?

PoC is better when users are spread across cities or countries, when the site changes frequently, or when building a radio network is impractical. It depends on mobile coverage, adds a subscription per user and has higher latency than conventional radio. For a single critical site with no mobile coverage, a repeater or a conventional network is usually more reliable.

Coverage & planning · 4 min read Coverage Planner: A 5-Minute Radio Coverage Self-Check Answer six questions about your building, area and users to see whether direct mode, a repeater, an indoor system or PoC fits a 500–10,000 m² site. Read guide → Technology selection · 6 min read Analog vs DMR vs PoC: How to Choose a Two-Way Radio System Compare analog, DMR and PoC radios on coverage, licence, encryption, battery and five-year cost, including 12.5 kHz DMR two-slot capacity. Read guide → Licensing & bands · 7 min read Walkie-Talkie License: Do You Need One? A Country Guide Do you need a licence for a walkie-talkie? Compare FRS, GMRS, PMR446 and business-band rules across the US, UK, EU and Gulf, with 2 W and 0.5 W limits. Read guide →