Know exactly what every mile costs you.
GarageWatts automatically tracks your home EV charging and shows your real cost per mile — based on your actual electricity rate, from your actual charging sessions.
No guessing. No factory app. No expensive subscription.
"How much am I actually paying?"
You've said it: EVs are cheaper to drive than gas cars. You probably believe it. But when someone asks for a number, most EV owners guess or pull out a complicated spreadsheet to try and get the number manually.
GarageWatts gives you the number. Not an industry average. Your actual cost per mile, from your actual charging sessions, at your actual electricity rate.
Two ways to track. Start today.
Option 1 — No hardware
Works for everyone
Log sessions manually, or let GarageWatts estimate kWh from your battery percentage before and after charging. Takes 30 seconds. Works with any EV, any charger level.
Option 2 — Automatic
Level 1 / 120V outlet only
Plug a Shelly Plug US Gen4 ($24.99) into your standard 120V wall outlet. Your charge cable plugs into the Shelly. GarageWatts captures every session automatically — kWh, start time, end time, cost in dollars. No forms to fill out.
Buy Shelly Plug on Amazon — $24.99Which outlet do I have?
A standard 120V outlet looks like any household outlet — three holes, the same as a lamp or phone charger. Your car's included charge cable plugs right into it. A 240V Level 2 outlet is larger (like a dryer outlet) or is a dedicated wall unit installed by an electrician. The Shelly Plug works with standard 120V outlets only.
Your factory app wants $25/month without cost per mile.
| Factory App | GarageWatts | |
|---|---|---|
| Monthly cost | $25/mo | Free |
| Cost per session | ||
| Cost per mile | ||
| Efficiency trends | ||
| Works on any EV | Limited | Any EV |
| Your data | ||
| Annual cost | $300 | $0 |
Everything you need. Nothing you don't.
To get started — no hardware needed
Create an account, add your vehicle, and start logging sessions in under a minute using battery percentage estimates or manual entry. Free, no credit card, no expiry.
Want automatic tracking?
Shelly Plug US Gen4
Level 1 / 120V home charging only
One-time purchase. No subscription. Plugs into your standard 120V outlet in 30 seconds — the same outlet your charge cable already uses.
Buy on AmazonLevel 2 / 240V charging: Automated tracking for dedicated wall EVSEs (ChargePoint, Emporia, Grizzl-E etc.) and Tesla integration is on the roadmap. You can use GarageWatts today with manual or SOC-based logging.
Start tracking for free
No credit card required. No trial period. No expiry. Log your first session in under 2 minutes.
Get started freeGarageWatts participates in the Amazon Associates Program and may earn a commission on qualifying purchases at no additional cost to you.