Best Cheap Smart Watches Under £40 in the UK (2026)

Not everyone wants — or needs — to spend upwards of £200 on a smartwatch just to track their steps, keep an eye on their heart rate, and see who's calling without digging their phone out of their bag. If you're after a genuinely useful, affordable cheap smart watch under £40 UK shoppers can actually rely on day to day, you're in the right place. This guide breaks down what to expect at this price point, what corners are (and aren't) cut, and which COLMI watches are worth your money right now.

What to Realistically Expect From a Sub-£40 Smart Watch

Budget smartwatches have come a long way. At under £40, you can now reasonably expect:

A colour touchscreen display, usually somewhere between 1.3" and 1.85"
Step, distance, and calorie tracking
Continuous or spot heart rate monitoring
Blood oxygen (SpO2) estimation
Sleep tracking
Multiple sport modes
Notification mirroring from your phone (calls, texts, app alerts)
Several days of battery life per charge

What you generally won't get at this price is built-in GPS (most budget watches rely on your phone's GPS via Bluetooth for outdoor route mapping), a premium metal build, or an always-on AMOLED display running at full brightness constantly. None of that is a dealbreaker for most people — it simply means you're paying for the essentials rather than flagship extras.

Why Buy a Budget Smart Watch Instead of a Cheap Fitness Band?

Fitness bands are cheaper still, but a budget smartwatch under £40 usually gives you a noticeably bigger, more usable screen, a proper touch interface rather than a single button, and a wider range of watch faces and sport modes. For most UK buyers who want something that looks and feels like a "real" smartwatch rather than a basic tracker, the extra few pounds is well spent.

What to Check Before You Buy

Display Size and Type

A bigger screen (1.7"–1.85") makes notifications and stats far easier to read at a glance, especially outdoors in daylight. Smaller screens (around 1.3") keep the watch slimmer and lighter on the wrist.

Battery Life

Most budget smartwatches in this bracket run for somewhere between 5 and 10 days of typical use, dropping faster if you have the screen brightness high or use call features heavily. Check the specific model's battery capacity if this matters to you.

Water Resistance

Look for at least an IP68 rating, which covers dust and everyday splashes, sweat, and rain. This is standard across most budget watches now, but always worth confirming before you buy if you plan to shower or swim with it on.

Call Handling

Many budget COLMI watches now support Bluetooth calling, meaning you can answer and end calls directly from your wrist when your phone is nearby — a genuinely handy feature at this price point that wasn't common a few years ago.

Companion App

Since the watch itself has a small screen, most of your detailed stats, trends, and settings live in the companion app. It's worth a quick look at what the app dashboard offers before choosing between models.

The Best COLMI Watches Under £40 in the UK

Here's a breakdown of the current lineup that fits comfortably under the £40 mark, based on published specifications.

Best Overall Value: COLMI P71 Smart Watch

The COLMI P71 Smart Watch is the most affordable model in the current range and covers all the fundamentals — heart rate, SpO2, sleep tracking, and multiple sport modes — in a lightweight design that's easy to wear all day without noticing it's there.

Best for a Bigger Display: COLMI P73 Smart Watch

If screen size is your priority, the COLMI P73 Smart Watch gives you a larger, easier-to-read display for checking notifications and stats at a glance, while staying well within budget.

Best All-Round Pick: COLMI C8 Max Smart Watch

The COLMI C8 Max Smart Watch balances a generous display with the full suite of everyday health tracking features, making it a solid choice if you want one watch that does everything reasonably well without overspending.

Best for Round-Face Fans: COLMI V72 Smart Watch

Not everyone wants a square or rectangular face — the COLMI V72 Smart Watch offers a classic round watch shape at a budget-friendly price, appealing to anyone who prefers a design that looks closer to a traditional wristwatch.

Best Everyday Fitness Companion: COLMI P76 Smart Watch

The COLMI P76 Smart Watch rounds out the everyday fitness tracking essentials — steps, heart rate, sleep, and sport modes — in a comfortable, lightweight case that's easy to wear from the gym to the office.

Also Worth a Look: COLMI P78 and COLMI P81

Both the COLMI P78 Smart Watch and COLMI P81 Smart Watch sit in a similar bracket, offering the same core tracking features with slightly different case shapes and strap styles, so it's worth comparing photos and colour options across the store to see which design suits you best.

Budget Watch vs Premium Watch: What Are You Actually Giving Up?

Stepping up from a sub-£40 watch to a pricier GPS-enabled model (like the COLMI V75 or V76) mainly buys you: standalone GPS for accurate outdoor route tracking without your phone, an AMOLED display for richer colours and deeper blacks, a compass and altimeter for outdoor navigation, and generally a more premium build. If you're mostly tracking daily steps, sleep, and heart rate around town, a budget watch covers the essentials perfectly well. If you're training for outdoor runs or hikes and want route mapping without carrying your phone, it's worth reading our separate guide on budget running watches.

Tips for Getting the Most Out of a Budget Smart Watch

Turn on raise-to-wake rather than always-on display to significantly extend battery life.
Set your correct step length and personal details in the app for more accurate distance and calorie estimates.
Charge it fully before first use, and try to keep it topped up rather than repeatedly running it flat to zero.
Update the companion app regularly, since firmware and app updates often improve accuracy and add features after launch.

Who Should (and Shouldn't) Buy a Budget Smart Watch

A sub-£40 smart watch is a genuinely sensible choice for a lot of people, but it's worth being clear-eyed about who benefits most.

A budget smart watch makes sense if:

You want the core basics — steps, heart rate, sleep, notifications — without paying for extras you'll rarely use.
You're buying your first smartwatch and aren't sure yet how much you'll actually use it.
You want a spare or backup watch alongside a more premium daily driver.
You're buying as a gift and want something genuinely useful without a big price tag.

You might want to spend more if:

You need standalone GPS for outdoor training without your phone.
You want an AMOLED display with richer colours and deeper blacks.
You're after a more premium metal build rather than a plastic or resin case.
You want advanced training metrics like recovery scores or multi-day training load tracking.

Common Mistakes to Avoid When Buying a Budget Smart Watch

Assuming "smart watch" always means built-in GPS. At this price point, most models rely on your phone's GPS via Bluetooth rather than an onboard chip — check the specifications rather than assuming.
Ignoring strap size and comfort. A watch that looks great in photos can feel bulky or slide around if the case and strap don't suit your wrist size, so check dimensions where available.
Not checking app compatibility first. While most budget watches work with both Android and iOS, always confirm compatibility with your specific phone before buying, particularly if you're on an older device.
Overlooking battery claims that assume minimal use. Manufacturer battery estimates often assume default settings with lower screen brightness and fewer notifications — real-world use, especially with calling features active, will usually be somewhat shorter.
Buying without checking colour and strap options. Many budget watches come in several colourways and strap materials, so it's worth browsing the full range before settling on the first option you see.

How Budget Watches Compare Across the COLMI Range

Within the sub-£40 bracket, the main differences between models tend to come down to screen size, case shape, and small feature additions like Bluetooth calling, rather than dramatically different sensor technology underneath. This is actually good news for buyers: it means you can largely choose based on the look and screen size you prefer, confident that the underlying health tracking will be broadly similar across the range. Where models do differ more meaningfully is in battery capacity and water resistance rating, so it's worth double-checking those two figures specifically if either matters a lot to your daily routine.

Setting Up Your Budget Smart Watch for the First Time

Getting a few basics right in the first few minutes makes a real difference to your ongoing experience:

Download the correct companion app for your specific model before pairing — check the product listing or included instructions, since budget watches sometimes use different apps across the range.
Enable notifications selectively rather than allowing everything through, so your watch buzzes for things that actually matter.
Set your personal details accurately (height, weight, age, step length if available) for more accurate calorie and distance estimates.
Choose a watch face that shows the information you check most, whether that's steps, heart rate, or the time and date front and centre.
Check for a firmware update shortly after pairing, since manufacturers often push accuracy and stability improvements after a model first goes on sale.

Battery-Saving Tips That Actually Make a Difference

If you want to stretch every extra day out of your budget smart watch's battery:

Lower the screen brightness a notch or two from the default setting.
Switch from an always-on display (if available) to raise-to-wake instead.
Turn off continuous heart rate monitoring overnight if you don't need sleep tracking, since constant sensor use is one of the bigger battery drains.
Limit vibration alerts to genuinely important notifications rather than every app on your phone.
Turn off Bluetooth calling features when you know you won't need them, since call handling tends to use more power than passive tracking.

Frequently Asked Questions

Can a smart watch under £40 track my sleep accurately? Yes, budget COLMI watches include sleep tracking that estimates duration and sleep stages using heart rate and movement data. It's a useful trend tool rather than a clinical-grade sleep study, but it works well for spotting patterns over time.

Do cheap smart watches have GPS? Most budget watches under £40 don't include standalone GPS chips; instead, they use your phone's GPS via Bluetooth when you're out for a walk or run. If you want a watch with its own built-in GPS, look at models like the COLMI V75 or V76.

Will a budget smart watch work with my iPhone? Yes, COLMI's budget watches are generally compatible with both Android and iOS through the companion app, though always double-check the specific model's listed compatibility before buying.

How waterproof are these watches? Most carry an IP68 rating, which protects against sweat, rain, and splashes. Always check the specific model's rating before wearing it in the shower or pool.

Is it worth spending more than £40 on a smart watch? It depends on your needs. If you want GPS, an AMOLED screen, or a more premium build, spending more makes sense. If you mainly want steps, sleep, heart rate, and notifications, a sub-£40 watch covers those needs very well.

Final Thoughts

A cheap smart watch under £40 no longer means a compromised experience — the current COLMI lineup covers heart rate, sleep, SpO2, and notifications at a genuinely accessible price. Whether you want the simplest possible entry point with the COLMI P71 or a bigger screen with the C8 Max, browse the full range in-store to compare colours and current pricing before you buy.

Best Cheap Smart Watches Under £40 in the UK