An ignition interlock device (IID) runs $60–$120 a month to lease, plus a $70–$150 installation, $20–$30 calibration visits every 30–60 days, and a $50–$100 removal. A 6-month first-offense program totals $610–$1,010 (mid-range: $760, or $126.67/mo effective); a 12-month term runs $1,045–$1,820. You pay every dollar of it — these are offender-paid costs.
Providers advertise the monthly lease because it's the smallest-looking number. The real budget has four parts:
Enter your provider quote, term, and calibration interval — get the true total and effective monthly cost.
Open the Ignition Interlock Cost Calculator →| Provider | Install | Monthly lease | Notes |
|---|---|---|---|
| Intoxalock | $70 – $150 | $78 – $120 | "As low as $1.96/day" advertised; typical $2.60–$4.00/day |
| Smart Start | from $150 | $60 – $85 | Warranty included; ~$200 vehicle transfer |
| LifeSafer | $50 – $150 | $50 – $120 | Big state-by-state spread |
| Draeger | $0 – $100 | ~$80 | Install often bundled into lease; removal ~$55 |
| Guardian | $70 – $170 | $50 – $90 | Common on state certified lists |
Advertised ranges, 2025. The practical takeaway: on a 6-month program the spread between providers is maybe $100–$200 — often less than the two fees you'd pay to switch mid-program. Choose on service-center proximity and scheduling, not on the teaser rate.
Your state's required term drives the total harder than any pricing decision:
| Term | Low ($60/mo) | Mid ($85/mo) | High ($120/mo) |
|---|---|---|---|
| 6 months | $610 | $760 | $1,010 |
| 12 months | $1,045 | $1,345 | $1,820 |
| 24 months | $1,915 | $2,515 | $3,440 |
First-offense terms where mandated commonly run 6 months in California, Florida, New York, and Texas; 8 in Colorado; about 12 in Arizona, Pennsylvania, and Washington. But the details that actually set your term — BAC level, test refusal, prior offenses, judge discretion — vary enormously, and several states only mandate the device for elevated-BAC first offenses or repeats. This is a check-with-the-court number, not a chart number.
Six-month California term, mid-range provider: $100 install + 6 × $85 lease ($510) + 3 calibration visits × $25 ($75) + $75 removal = $760. That's $126.67 a month effective, or $4.17 a day — well above the "$2.75/day" a quote might headline, because the fixed fees amortize over a short term. The same setup over Arizona's 12 months: $1,345, an effective $112.08 a month. Longer terms dilute the fixed costs; that's the one small mercy of a longer requirement.
The IID is also only one line of the post-DUI budget. An SR-22 filing and the high-risk insurance tier usually cost more per month than the device itself — the SR-22 insurance cost calculator prices that stack, and the rate increase calculator estimates the surcharge itself. Before the fact, the BAC calculator is the cheaper tool by several thousand dollars.
Three legitimate levers: ask about low-income fee reductions — several states have them and providers don't advertise them; keep every calibration appointment, since violations extend terms and lockouts cost fees; and quote two or three certified providers locally before signing, because install promos come and go. What doesn't work: skipping payments (the device reports it), shopping for a device online (states certify providers), or borrowing someone else's car without an interlock (a new, worse offense). Drive the term cleanly, pay the stack once, and it ends.
$60-$120 per month for the lease, with most invoices landing near $80-$90. Teaser rates as low as $1.96/day are real but rare — real-world billing clusters at $2.60-$4.00 per day once monitoring and state fees stack on. Budget on the program total, not the headline rate.
Installation runs $70-$150, calibration or service visits run $20-$30 every 30-60 days, removal runs $50-$100 at the end, and vehicle transfers cost $100-$200. Missed appointments can trigger lockout service fees. A 6-month program's bookend fees add roughly $250-$350 on top of the lease itself.
Advertised ranges overlap heavily: Smart Start leases from about $60/month but charges from $150 to install; Draeger often bundles a low install fee into an ~$80/month lease; Guardian runs $50-$90/month. The spread between major providers on a 6-month program is usually $100-$200 — often less than the cost of switching mid-program, so service quality and a nearby service center usually matter more than price.
Where states mandate IIDs for a first offense, terms commonly run 6 to 12 months: California, Florida, New York, and Texas at roughly 6 months; Colorado at 8 months; Arizona, Pennsylvania, and Washington at about 12. Terms depend on BAC level, refusal, and judge discretion, and several states only mandate the device for higher-BAC or repeat offenses. Verify yours with the DMV or court.
Some states offer fee reductions or waivers for verified low-income participants, and a few credit part of the cost against fines. The programs exist but providers rarely advertise them — ask the court clerk or monitoring authority directly. What nobody offers is insurance coverage: auto policies do not pay for interlock devices.