Best Fertility Apps & Tools UK
These six range from a £8.99-a-month app to a £249 wearable, and the price mostly buys you more direct physiological data rather than pure prediction. Flo Premium (£8.99/month) is the most widely used and easiest to start with — AI-predicted fertile windows and symptom logging with no hardware to buy — but its predictions are exactly that, predictions, not physiological confirmation, and get less reliable with a genuinely irregular cycle.
Femometer's Bluetooth basal thermometer (£25.99) and Natural Cycles' app (from £90, paired with a thermometer) both use body temperature to confirm ovulation has actually happened, with Natural Cycles going further as a clinically validated algorithm with published studies behind it — stronger evidence than most tracking apps, at a real subscription cost with no free tier.
Clearblue's Advanced Fertility Monitor (£64.99) tracks two actual hormones via daily test sticks, reading directly on the device with no app needed, though ongoing test stick refills add up over multiple cycles. Mira's Plus monitor (£200) and Ava's bracelet (£249) go furthest: Mira gives quantified hormone concentration numbers rather than a simple positive/negative, useful alongside a fertility specialist, while Ava is fully passive — no test strips at all, just overnight wear — predicting the fertile window up to five days in advance from multiple physiological signals.
No product here is sponsored to be called "the best" — see our editorial policy for how we choose and score picks.
Full comparison
 |  |  |  |  |  | |
|---|---|---|---|---|---|---|
| Price | Around £249 one-off for the bracelet | Around £200 for the analyser (wands sold separately) | £64.99 (monitor + 10 test sticks), refills from £29.99 | £25.99 | £8.99/month or £39.99/year | Around £90/year subscription (thermometer often included) |
| Overall score | 7.7/10 | 6.9/10 | 7.1/10 | 7.8/10 | 7.7/10 | 7.5/10 |
| Format | Wrist-worn bracelet + companion app | Analyser device + disposable test wands | — | — | — | — |
| Tracking method | Multi-signal overnight wearable (temperature, pulse, breathing) | Quantified LH/estrogen hormone analysis | — | — | — | Basal temperature + cycle data algorithm |
| Connectivity | — | Bluetooth, companion app | — | Bluetooth, syncs to Femometer app | — | — |
The verdict
If you want to try tracking with no upfront cost, Flo Premium is the easy starting point, though it's prediction rather than confirmation. For genuine physiological confirmation, Femometer's basal thermometer is the cheapest route in, and Natural Cycles is worth its subscription if you want a clinically validated algorithm behind the readings. Clearblue's monitor is the middle ground — real hormone tracking with no app required. Only go for Mira or Ava if you want the most detailed data possible, ideally alongside a fertility specialist who can make use of it — for most people trying to conceive, they're more than's needed.
Read the full reviews
- Ava Ava Fertility Tracking Bracelet review →
- Mira Mira Plus Fertility Hormone Monitor review →
- Clearblue Advanced Fertility Monitor review →
- Femometer Vinca Bluetooth Basal Body Thermometer review →
- Flo Health Flo Premium — Cycle & Fertility Tracker review →
- Natural Cycles Natural Cycles — Cycle & Fertility Tracker review →