When you open a location test or a maps app, you often see a number like "Accuracy: 8 m" or a circle drawn around your position. But what does that number actually mean — and what accuracy should you expect from a phone GPS? Here's a practical breakdown.
What Is the GPS Accuracy Radius?
The accuracy radius is not the error in your reported position — it's a confidence circle. Your true location is estimated to be somewhere within that circle, with the reported coordinates at the center. A radius of 5 m means the device is highly confident your real position is within a 5-metre circle. A radius of 300 m means it's much less certain.
This value comes from the browser's Geolocation API, which combines signals from GPS satellites, Wi-Fi positioning, and cell towers and reports the confidence it has in the resulting fix.
What Counts as Good GPS Accuracy in Meters?
| Accuracy Radius | Quality | Likely Source |
|---|---|---|
| Under 5 m | Excellent | Full satellite lock, clear sky, dual-frequency GNSS |
| 5–10 m | Very good | Strong GPS lock outdoors |
| 10–30 m | Good | GPS with some obstruction (trees, light cover) |
| 30–100 m | Moderate | Partial GPS + Wi-Fi assist, urban canyon |
| 100–500 m | Poor | Wi-Fi positioning only, indoors |
| Over 500 m | Very poor | Cell tower triangulation, no GPS or Wi-Fi lock |
For everyday navigation, anything under 30 m is perfectly usable. For fitness tracking, hiking, or precise mapping, you want to be under 10 m. Indoors, expect 50–200 m — the GPS signal simply cannot penetrate walls, so the device falls back to Wi-Fi and cell data.
How Accurate Is Phone GPS?
Modern smartphones are surprisingly capable GPS receivers. Here's how they compare to other GPS devices under good outdoor conditions:
- Flagship phones with dual-frequency GNSS (e.g. Pixel 6+, iPhone 14+, Samsung Galaxy S21+) — typically 1–5 m
- Mid-range phones, single-frequency GPS — typically 3–10 m
- Budget phones — 5–20 m under good conditions
- Dedicated consumer GPS receiver (hiking device) — 3–5 m
- Survey-grade GNSS receiver — centimetre level
The practical takeaway: a modern flagship phone is as good as or better than a dedicated hiking GPS. The gap shows up indoors and in dense urban areas, where the small antenna and phone-side signal processing struggle more than a specialized receiver.
GPS Accuracy vs Precision: What's the Difference?
These two terms are often used interchangeably but mean different things in positioning:
- Accuracy — How close your reported position is to your true position. A reading 2 m from your actual location is highly accurate.
- Precision — How consistent or repeatable your readings are. If you stand still and take 10 readings, do they all cluster together, or do they scatter?
A GPS can be precise but inaccurate: every reading lands in the same spot, but that spot is consistently 50 m from where you actually are. This happens with systematic errors like a poorly calibrated sensor or a VPN routing location through a distant city. For real-world navigation and testing, accuracy is the number that matters most.
What Affects Your GPS Accuracy Radius?
Several factors push the accuracy radius up or down:
- Sky visibility — Every wall, roof, and dense canopy that blocks satellite signals widens your accuracy circle.
- Number of satellites locked — More satellites means better triangulation. Modern phones can track signals from multiple constellations (GPS, GLONASS, Galileo, BeiDou) simultaneously.
- High-accuracy mode — Android's high-accuracy mode and iOS's Precise Location both enable full satellite use. Battery saver modes reduce or eliminate GPS use.
- Multipath error — In urban canyons (streets surrounded by tall buildings), satellite signals bounce off glass and steel before reaching your antenna, introducing timing errors that widen the radius and cause GPS drift.
- Cold start vs warm start — A GPS chip that hasn't been used in hours needs 1–3 minutes to reacquire satellites (cold start). One used recently locks in seconds (warm start).
- VPN and IP geolocation — If GPS is unavailable and the browser falls back to IP geolocation, a VPN can route your IP through a city in another country, producing wildly inaccurate results.
Check Your Phone's GPS Accuracy Right Now
The fastest way to see your actual accuracy radius is to open the Location Accuracy Test, tap Start GPS Scan, and allow location access. The tool shows your accuracy radius in real time as the GPS locks on — you can watch the number shrink as the fix improves. Try it indoors, then step outside and compare.
📍 See your accuracy radius live: The MyDeviceScan Location Accuracy Test shows your GPS fix quality in real time — accuracy radius, coordinates, altitude, speed, and heading — all in your browser with no install needed.
Frequently Asked Questions
What is a good GPS accuracy in meters?
For a smartphone, an accuracy radius under 10 metres is excellent and means you have a solid satellite lock. Between 10–30 m is good and typical outdoors near some cover. 30–100 m is moderate, usually meaning partial GPS with Wi-Fi assist. Over 100 m means GPS is not active and location is coming from Wi-Fi or cell towers instead.
What does the GPS accuracy radius mean?
The accuracy radius is a circle around your reported position — your true location is estimated to be somewhere inside that circle. A radius of 5 m means the device is very confident. A radius of 500 m means it could place you anywhere within roughly 10 city blocks. Smaller is always better.
How accurate is phone GPS compared to a dedicated GPS device?
Dedicated GPS receivers used for hiking or surveying typically achieve 3–5 m accuracy, with survey-grade units reaching centimetre level. Modern smartphones with dual-frequency GNSS (common on flagship phones from 2019 onward) get close to 1–3 m outdoors. Budget phones without dual-frequency typically land in the 3–10 m range under good conditions.
What is the difference between GPS accuracy and precision?
Accuracy measures how close your reported position is to your true position. Precision measures how repeatable or consistent the readings are. A GPS can be precise (always reports the same coordinates) but inaccurate (those coordinates are consistently wrong). For navigation, you want both — but accuracy is the more practically important of the two.
Why does my accuracy radius jump between readings?
The accuracy radius changes because the GPS chip continuously adjusts its estimate as it receives signals from more or fewer satellites. Moving between areas with clear sky and obstructions (buildings, trees), a satellite rising or setting over the horizon, or multipath reflections from nearby buildings can all cause the radius to expand or shrink between readings.