Uninsured Motorist Coverage Need Calculator
Calculate how much uninsured motorist coverage you need based on medical costs, lost wages, and the rate of uninsured drivers in your state.
Underinsured Motorist Coverage Gap Calculator
Calculate the coverage gap when an at-fault driver's insurance isn't enough. See how much underinsured motorist coverage fills the shortfall.
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Coverage Gap⧉
$95,000.00
Damages ($120,000.00) − at-fault coverage ($25,000.00)
UIM Payout⧉
$95,000.00
79.2% of total damages covered by your UIM
Your Out-of-Pocket⧉
$0.00
Fully covered!
Coverage Status⧉
Adequate
UIM covers the full gap
Coverage Utilization⧉
95.0%
$95,000.00 of $100,000.00 used
Cost Per $1K Coverage⧉
$1.20
Annual premium per $1,000 of UIM coverage
Per-Passenger Exposure⧉
$0.00
Out-of-pocket split among 1 passenger
Meets State Minimum⧉
Yes
State requires $25,000.00 minimum
Damage Coverage Breakdown
At-fault
Your UIM
Estimated Damage Breakdown
| Category | % of Total | Est. Amount | Share |
|---|---|---|---|
| Medical Bills | 45% | $54,000.00 | |
| Lost Wages | 20% | $24,000.00 | |
| Pain & Suffering | 25% | $30,000.00 | |
| Property Damage | 5% | $6,000.00 | |
| Rehabilitation | 5% | $6,000.00 |
UIM Limit Comparison
| UIM Limit | UIM Pays | Out-of-Pocket | Est. Annual Premium | Adequate? |
|---|---|---|---|---|
| $25,000.00 | $25,000.00 | $70,000.00 | $30.00/yr | ✗ |
| $50,000.00 | $50,000.00 | $45,000.00 | $60.00/yr | ✗ |
| $100,000.00 | $95,000.00 | $0.00 | $120.00/yr | ✓ |
| $250,000.00 | $95,000.00 | $0.00 | $300.00/yr | ✓ |
| $500,000.00 | $95,000.00 | $0.00 | $600.00/yr | ✓ |
At-Fault Coverage Scenarios
| At-Fault Limit | Gap | UIM Pays | Your Cost |
|---|---|---|---|
| Uninsured | $120,000.00 | $100,000.00 | $20,000.00 |
| $15,000.00 | $105,000.00 | $100,000.00 | $5,000.00 |
| $25,000.00 | $95,000.00 | $95,000.00 | $0.00 |
| $50,000.00 | $70,000.00 | $70,000.00 | $0.00 |
| $100,000.00 | $20,000.00 | $20,000.00 | $0.00 |
Planning notes, formulas, and examples
About the Underinsured Motorist Coverage Gap Calculator
Even when the at-fault driver has insurance, their policy may not be enough to cover your injuries. If a driver carrying only state minimum liability ($25,000) causes an accident that gives you $100,000 in medical bills, you're left with a $75,000 gap. Underinsured motorist (UIM) coverage fills that shortfall.
This calculator shows the gap between your potential damages and the at-fault driver's likely coverage. Enter your estimated damages and the at-fault driver's coverage level to see how much UIM protection you'd need.
This is an educational estimator only — not an actual insurance quote or recommendation. Speak to a licensed insurance agent for personalized advice.
When This Page Helps
Many drivers carry only state minimum liability limits, which can be as low as $15,000-$25,000 per person. A single ER visit with surgery can exceed $100,000. UIM coverage bridges the gap between what the other driver's insurance pays and your actual costs. This calculator quantifies that gap.
How to Use the Inputs
- Enter your total estimated damages (medical + lost wages + property).
- Enter the at-fault driver's liability coverage limit.
- Enter your current UIM coverage limit (or 0 if none).
- Review the coverage gap and whether your UIM is sufficient.
- Adjust your UIM coverage based on the analysis.
Formula used
Coverage Gap = Total Damages − At-Fault Driver's Liability Limit
UIM Payout = min(Coverage Gap, Your UIM Limit)
Remaining Out-of-Pocket = Coverage Gap − UIM Payout
UIM Adequate = Your UIM Limit ≥ Coverage GapExample Calculation
Result: $95,000 gap — your $100K UIM covers it
Your total damages are $120,000 but the at-fault driver only has $25,000 in liability coverage. That leaves a $95,000 gap. Your $100,000 UIM coverage is sufficient to cover the shortfall, leaving $0 out of pocket.
Tips & Best Practices
- Many drivers carry only $25,000-$50,000 liability — well below what a serious accident costs.
- Match your UIM limits to your own liability limits for balanced protection.
- UIM coverage is one of the least expensive add-ons to your auto policy.
- Some states offer "difference" UIM and "offset" UIM — understand which your state uses.
- UIM property damage (UIMPD) is available in some states for vehicle damage shortfalls.
- This is an educational estimate — consult a licensed insurance professional.
The Underinsured Driver Problem
While about 13% of drivers are completely uninsured, a much larger percentage carry only state minimum liability limits. In many states, minimums are $15,000-$25,000 per person — barely enough to cover a routine ER visit. A serious injury can easily generate six-figure medical bills.
Difference vs Excess UIM
States handle UIM payouts differently. In "difference" states, your UIM limit must be higher than the at-fault driver's liability for you to receive any payment. In "excess" states, UIM pays on top of whatever the other driver's insurance provides. Know your state's approach.
Practical UIM Strategy
Setup your UIM limits to match your own liability limits. If you carry 100/300/100 liability, carry 100/300 UIM as well. This ensures consistent protection regardless of which side of an accident you're on.
Sources & Methodology
Last updated:
Frequently Asked Questions
Underinsured motorist (UIM) coverage pays the difference when an at-fault driver's insurance isn't enough to cover your damages. If you have $75,000 in medical bills and the at-fault driver has only $25,000 in liability coverage, UIM covers the $50,000 gap up to your UIM limit.
UM (uninsured motorist) coverage applies when the at-fault driver has NO insurance. UIM (underinsured motorist) applies when they have insurance but not ENOUGH. Together, they protect you whether the other driver has no coverage or insufficient coverage.
In most states, you first collect from the at-fault driver's liability policy up to their limit. Then your UIM coverage pays the remaining damages up to your UIM limit. Some states use "difference" coverage (your UIM minus their liability), while others use "excess" coverage.
Requirements vary by state. Some states mandate UIM coverage, others offer it as optional, and some don't offer it at all. Even where optional, it's strongly recommended given the prevalence of minimally insured drivers.
UIM coverage is relatively inexpensive, typically adding $20-$75 per year to your policy depending on your coverage limits and location. For the protection it provides, it's one of the best values in auto insurance.
Some states allow UIM stacking, which multiplies your coverage by the number of vehicles on your policy. With $100,000 UIM and three cars, stacking gives you $300,000 in UIM protection. Check your state's rules.
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