The monthly premium is the number everyone shops, but it is almost never the number that decides whether a health plan is a good deal. The real cost of health insurance is built from five stacked parts: the premium you pay no matter what, the deductible you pay before the plan shares anything, the coinsurance you pay after the deductible, the out-of-pocket maximum that caps your exposure, and the medical spending you actually expect to have. This health insurance calculator stacks all five together and returns your true expected annual cost, so you can compare two plans on what you will actually write the check for rather than on a monthly sticker price.
Adjust any field and the result card updates instantly. The most useful way to use it is to run the same expected-spending number through two or three competing quotes and watch which one wins in a good year versus a bad year.
How to Use
- Enter the Monthly Premium — the recurring amount the insurer quotes you each month, usually auto-paid from your paycheck or bank account.
- Set the Annual Deductible. This is what you pay in full for covered in-network care before coinsurance begins. A $3,000 deductible means the first $3,000 of bills are yours.
- Enter the Out-of-Pocket Maximum. Federal rules cap this number in a marketplace plan; once your deductible plus coinsurance adds up to it, the plan pays 100% of covered in-network care for the rest of the year.
- Set the Coinsurance (Your Share) as a percentage of the bill you pay after the deductible. A 20% coinsurance means the plan covers 80% and you cover 20% of the remaining allowed amount.
- Estimate your Expected Medical Spending for the coming year. Be honest: include predictable drugs, a planned procedure, a couple of specialist visits, and routine labs. If you are healthy, leave it near $0; if you manage a chronic condition, use last year's total.
- Read the result card: the annual premium, the deductible you would pay, your coinsurance share, the total out-of-pocket capped at your maximum, and the Expected Total Annual Cost — the number you should actually compare across plans.
The Cost-Sharing Waterfall
A health plan pays out in a fixed order, which is exactly how this calculator works:
Annual cost = (monthly premium × 12) + min(medical spending, deductible) + coinsurance% × max(0, medical spending − deductible), capped at the out-of-pocket maximum.
Walk through the defaults: a $450 monthly premium is $5,400 a year. If you expect $5,000 of covered care, you pay the first $3,000 (the full deductible). The remaining $2,000 splits at 20% coinsurance — you owe $400, the plan owes $1,600. Your out-of-pocket total is $3,000 + $400 = $3,400, well under the $6,000 maximum. Add the premium and your true annual cost is $8,800.
Now imagine a catastrophic year with $200,000 of bills. Without a cap you would owe $3,000 plus 20% of $197,000 = $42,400. But the $6,000 out-of-pocket maximum stops you there. Your total for the year is still only $5,400 + $6,000 = $11,400 — which is the whole point of buying insurance.
Premium vs Deductible: The Real Trade-off
Shopping on premium alone usually picks a Bronze plan. Shopping on this calculator usually changes that decision.
- High-premium / low-deductible plan (Gold): $550/month, $1,000 deductible, $4,000 OOP max, 20% coinsurance. A healthy family spending $5,000 pays about $6,600 a year.
- Low-premium / high-deductible plan (Bronze): $280/month, $7,000 deductible, $9,000 OOP max, 40% coinsurance. That same $5,000 of spending is entirely within the deductible, so the family pays $3,360 premium + $5,000 out of pocket = $8,360.
The cheap-looking Bronze plan actually costs $1,760 more in a normal medical year — and it only wins if you stay nearly completely healthy. Flip the expected spending to $30,000 and the Bronze plan hits its out-of-pocket cap and finishes around $13,560, while the Gold plan finishes near $10,900. Run your own numbers before you renew.
Examples
Example 1 — A healthy single person. Monthly premium $380, deductible $2,500, out-of-pocket max $5,000, coinsurance 20%, expected spending $600 (one urgent-care visit). Annual premium is $4,560. The $600 never reaches the deductible, so deductible paid is $600, coinsurance $0. True annual cost: $5,160. The low deductible never mattered.
Example 2 — A family with a planned surgery. Premium $620/month, deductible $6,000, OOP max $12,000, coinsurance 20%, expected spending $40,000. Premium is $7,440. They pay the $6,000 deductible, then 20% of the remaining $34,000 = $6,800. Out-of-pocket total is $12,800, which is capped down to the $12,000 maximum. True annual cost: $19,440, with the plan picking up $28,000 of the bills.
Example 3 — Comparing two employer plans. Plan A costs $350/month with a $1,500 deductible and $3,000 OOP max. Plan B costs $180/month with a $7,000 deductible and $9,000 OOP max. At $8,000 of expected spending, Plan A runs about $4,200 + $1,500 + $1,300 = $7,000, while Plan B runs $2,160 + $7,000 + $300 = $9,460. The cheaper monthly plan is the more expensive one this year.
FAQ
How is the true cost of health insurance calculated?
You add the annual premium (monthly premium × 12) to your expected share of medical bills. That share is the full deductible up to your spending, plus your coinsurance percentage on every bill after the deductible, capped at the out-of-pocket maximum. This calculator applies exactly that waterfall and shows each layer separately.
What is the difference between a deductible and an out-of-pocket maximum?
The deductible is the amount you pay for covered care before coinsurance starts. The out-of-pocket maximum is the yearly ceiling on everything you pay — deductible plus coinsurance combined. Once you reach it, the insurer pays 100% of covered in-network care. The deductible always counts toward the out-of-pocket maximum.
Should I pick the plan with the lowest monthly premium?
Not automatically. A low premium plan almost always carries a high deductible. If you expect any routine care, prescriptions, or a procedure, that high deductible can cost you more over the year than the premium you saved. Run your expected spending through this calculator for each plan before deciding.
What happens after I hit my out-of-pocket maximum?
For the rest of that plan year, the insurer pays 100% of covered in-network essential health benefits. Your share drops to zero (copays may still apply depending on the plan). In this calculator, that is why the out-of-pocket line freezes at the maximum no matter how high you push expected medical spending.
Does coinsurance apply before or after the deductible?
Coinsurance applies only to spending above the deductible. If your deductible is $3,000, coinsurance 20%, and you have $5,000 of bills, you pay the first $3,000 in full and then 20% of the remaining $2,000 ($400). The plan pays the other 80% of that remainder.
Are premiums counted toward my deductible?
No. Premiums are the price of the policy and never count toward the deductible or the out-of-pocket maximum. Only what you pay for actual covered medical care — deductible, coinsurance, and copays — accumulates against those caps.
What counts as expected medical spending?
Use your best forecast of in-network, covered charges: office visits, specialist visits, urgent care, labs, imaging, prescriptions on your plan's formulary, and any scheduled surgery or therapy. Out-of-network balance bills and non-covered elective procedures usually do not count the same way, so read the plan's summary of benefits before entering numbers.
Disclaimer
This health insurance calculator is provided for informational purposes only and is not medical advice, nor a quote, endorsement, or recommendation of any specific insurance carrier, plan, or treatment. Estimates rely entirely on the inputs you enter and on the standard deductible–coinsurance–out-of-pocket-maximum cost-sharing waterfall; real plan design includes copays, network tiers, prior authorization, excluded services, and deductible resets that this tool does not model. Actual costs vary by insurer, region, network, family size, and plan year. Always read your plan's Summary of Benefits and Coverage and confirm your expected costs directly with a licensed insurance agent, your HR benefits office, or HealthCare.gov before you enroll or change coverage.