Home › Calculators › Health Insurance Coinsurance Calculator
Health Insurance Coinsurance Calculator
Estimate your share of a medical bill. Enter the allowed amount, your deductible and how much you've met, your copay, coinsurance percentage and out-of-pocket maximum to see exactly what you pay, what insurance pays and how much of your deductible and maximum is left.
Last updated:
The bill
$
The amount your plan allows, shown on the Explanation of Benefits (EOB).
Your plan
$
$
%
An 80/20 plan means you pay 20%.
$
$
Leave 0 if your plan has none.
$
Deductible, coinsurance and copays paid so far this year.
Enter your values to see the result.
Advertisement
Advertisement
How to use the Health Insurance Coinsurance Calculator
- Enter the medical bill, ideally the allowed amount from your Explanation of Benefits rather than the provider's list price.
- Choose how the service is covered: deductible then coinsurance, a copay first, or a copay only.
- Enter your plan details: deductible, how much you have met, coinsurance % and any copay.
- Add your out-of-pocket maximum and what you have already paid toward it this year.
- Press Calculate my cost to see your share, the insurer's share and a table of costs at other bill sizes.
How your share of a medical bill is calculated
- Remaining deductible = deductible − amount already met.
- Deductible portion = the smaller of the bill and the remaining deductible. You pay this in full.
- Coinsurance = (bill − deductible portion) × your coinsurance %.
- Add any copay that applies to the service.
- Cap: you never pay more than what is left of your out-of-pocket maximum. Insurance pays the rest.
Example: a $25,000 hospital bill with a $2,000 deductible ($500 already met), 20% coinsurance and a $6,000 maximum ($900 already paid). Without the cap you would owe $1,500 + 20% × $23,500 = $6,200, but only $5,100 of your maximum is left, so you pay $5,100 and the plan pays $19,900.
Common cost-sharing terms
| Term | What it means | Counts toward out-of-pocket max? |
|---|---|---|
| Premium | Monthly price of the plan | No |
| Deductible | What you pay before the plan starts sharing costs | Yes |
| Copay | Fixed fee per visit or prescription | Yes |
| Coinsurance | Your percentage of costs after the deductible | Yes |
| Allowed amount | Negotiated price the plan uses for cost sharing | n/a |
| Balance bill | Out-of-network charge above the allowed amount | Usually no |
Tips to estimate costs before care
- Ask your provider for the billing codes and your insurer for an estimate of the allowed amount; many insurers have cost-estimate tools.
- Family plans often have both an individual and a family deductible and maximum. Use the individual figures for one person's bill unless the family amount will be reached first.
- Preventive services such as many screenings and vaccines are often covered with no cost sharing in network.
- If you have an HSA or FSA, you can pay your share with pre-tax money.
- Scheduling several procedures in the same plan year can mean the later ones cost less once the deductible or maximum is met.
Frequently asked questions
How does coinsurance work with a deductible?
You first pay the full allowed amount until your deductible is met. After that you pay your coinsurance percentage of the rest and the plan pays the remainder. For a $4,000 bill with $1,500 of deductible left and 20% coinsurance, you pay $1,500 + 20% of $2,500 = $2,000.
What is the difference between a copay and coinsurance?
A copay is a fixed dollar amount for a service, such as $30 for a doctor visit. Coinsurance is a percentage of the allowed cost, such as 20%. Many plans use copays for office visits and prescriptions and coinsurance for hospital care, surgery and imaging.
What does an out-of-pocket maximum do?
It is the most you pay in a plan year for covered in-network care. Deductible, coinsurance and copays all count toward it. Once you reach it, the plan pays 100% of covered services for the rest of the year. Premiums do not count toward the maximum.
What does 80/20 coinsurance mean?
After you meet your deductible, the insurer pays 80% of the allowed amount and you pay 20%, until you reach your out-of-pocket maximum. Other common splits are 90/10 and 70/30.
Why should I use the allowed amount instead of the billed amount?
In-network providers agree to accept the plan's negotiated rate, called the allowed amount, which is often much lower than the original charge. Your deductible and coinsurance are calculated on the allowed amount, which appears on your Explanation of Benefits.
Does this include out-of-network or non-covered costs?
No. Out-of-network care can have a separate deductible and maximum, and providers may bill you for the difference between their charge and the allowed amount. Services your plan does not cover are paid in full by you and usually don't count toward the maximum.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.
Related tools
HSA CalculatorEstimate HSA tax savings and project your health savings account balance over time.Budget CalculatorMonthly budget planner with the 50/30/20 rule and a donut chart.Percentage CalculatorWork out percentages, increases and decreases.Couple Expense Split CalculatorSplit shared household bills between partners by income, 50/50, equal leftover or custom %.Tip CalculatorWork out the tip and split the bill between any number of people.Discount CalculatorSale price, percent off, stacked discounts and sales tax.Emergency Fund CalculatorFind how big your emergency fund should be and how long it takes to save it, with interest.Wedding Budget PlannerSplit a wedding budget by category, then track estimated, actual and paid costs with a chart.Split Bill CalculatorSplit a bill with tax and tip equally, by shares, or by what each person ordered.50/30/20 Budget CalculatorSplit take-home pay into needs, wants and savings with the 50/30/20 rule or your own split.TikTok Money CalculatorEstimate TikTok sponsored post rates and Creator Rewards earnings from your views.Rent Split CalculatorSplit rent fairly between up to 6 roommates by room size, income or equally.Grocery Budget CalculatorRecommended weekly or monthly grocery budget and cost per meal for your household.Latte Factor CalculatorSee what a small daily habit costs per year and what it could grow to if invested.Money CounterCount cash by bill and coin: subtotals, grand total, piece count and a printable count sheet.Savings Rate CalculatorFind your savings rate on net or gross pay and estimate years to financial independence.Sinking Fund CalculatorPlan monthly and biweekly savings for several goals with due dates and progress bars.Subscription Cost CalculatorTotal your subscriptions per month, year and decade, and see what the money could grow to.CBM CalculatorCarton cubic meters and cubic feet, 20ft/40ft/40HC container fit and sea/air chargeable weight.Cost of Living CalculatorCompare living costs in two US cities and find the salary you need after a move.52 Week Savings ChallengePlan a 52-week money challenge, tick off each deposit and print the savings chart as a PDF.Income Percentile CalculatorSee where your household or individual income ranks in the US, with an age-group option.Life Insurance CalculatorEstimate how much life insurance you need with the DIME method: debts, income, mortgage, education.Baby Cost CalculatorFirst-year baby budget: diapers, formula, childcare, gear and healthcare, monthly and yearly.Bank Statement AnalyzerUpload a bank CSV to sort spending into categories, see monthly charts and your top merchants.Change CalculatorEnter the amount due and cash paid to get the change owed and the bills and coins to give back.Christmas Budget CalculatorPlan holiday spending: gift list, decor, food and travel vs your budget and income.Weighted Decision MatrixScore options against weighted criteria to get a ranked total, a score heatmap and a CSV.Financial Ratio AnalyzerEnter an income statement and balance sheet once and get 30 liquidity, leverage and profit ratios.Freight Class CalculatorEstimate LTL freight class from density (lb per cubic foot) for one or many pallets.FSA CalculatorFlexible spending account tax savings, use-it-or-lose-it risk and the best amount to elect.FTE CalculatorConvert part-time hours into full-time equivalents, FTE into headcount, plus an ACA FTE count.Global Income Percentile CalculatorSee how your income per person compares with the whole world, adjusted for PPP.Health Insurance Plan Comparison CalculatorCompare health plans' total yearly cost at low, medium and high medical use, with break-even points.100 Envelope ChallengeTrack the 100 envelope savings challenge ($5,050), pick random envelopes and print the chart.Pallet CalculatorFind how many boxes fit on a pallet: boxes per layer, layers, total, height and weight.Pet Cost CalculatorMonthly, yearly and lifetime cost of a dog or cat: food, vet, insurance, grooming and more.1031 Exchange CalculatorDeferred and taxable gain on a like-kind exchange, with boot, recapture and new basis.Recurring Charges FinderOpen a bank CSV to find recurring subscriptions by merchant and interval, with annual costs.T-Account & Journal Entry GeneratorEnter debit and credit journal entries to get T-accounts and a balanced trial balance.Warehouse Space CalculatorSquare footage and rent for your pallets from rack levels, aisle %, staging and office space.Twitch Earnings CalculatorEstimate a streamer's monthly and yearly Twitch income from subs, bits, ads and sponsors.Zero-Based Budget CalculatorGive every dollar a job: assign income to categories until zero is left, with % and chart.Kids Allowance CalculatorKids weekly allowance by age, chore bonus and Save / Spend / Give jar split.Altman Z-Score CalculatorBankruptcy-risk Z-score for public, private and non-manufacturing companies, with zones.Budget Variance CalculatorBudget vs. actual by line: dollar and percent variance with favorable or unfavorable flags.Cohort Retention Table GeneratorTurn signup and activity data or cohort counts into a cohort retention heatmap and export it.Cost Basis CalculatorEnter buy and sell lots to get cost basis and realized gains by FIFO, LIFO, HIFO, average or specific ID.CSAT Score CalculatorCustomer satisfaction % from 1–5 rating counts or scores, plus CES average.Disability Insurance CalculatorMonthly income replacement need, existing coverage after tax and your disability benefit gap.Earned Value CalculatorProject EVM metrics: CV, SV, CPI, SPI, EAC, ETC, VAC and TCPI from BAC, PV, EV and AC.Follower Growth Rate CalculatorFollower growth rate between two dates, average daily gain and your next milestone date.Insurance Deductible CalculatorCompare a low vs high deductible: break-even claims, premium savings and expected yearly cost.Option Greeks CalculatorDelta, gamma, theta, vega and rho for calls and puts, with position Greeks and sensitivity charts.OTE Calculator (On-Target Earnings)On-target earnings, pay mix and total pay at any attainment with accelerators.Overhead Rate CalculatorOverhead rate per labor hour, machine hour or % of direct cost, applied to a job's cost.PERT CalculatorThree-point PERT estimates: expected duration, standard deviation and confidence ranges.Pivot Point CalculatorClassic, Fibonacci, Camarilla, Woodie and DeMark pivots with support and resistance levels.PPC Budget CalculatorAd budget and daily spend to hit a conversion or revenue goal from CPC and conversion rate.Project Budget CalculatorLine-item project budget: labor hours × rates, materials, overhead and contingency by phase.Repeat Purchase Rate CalculatorRepeat customer rate, purchase frequency and average days between purchases from your orders.Student Aid Index (SAI) EstimatorSimplified FAFSA Student Aid Index from income, assets and family size, with a Pell Grant hint.Utility Bill SplitterSplit electric, gas, water and internet bills among roommates by days, room size or shares.Absenteeism Rate CalculatorAbsence rate from days lost vs scheduled, cost of absenteeism and Bradford factor.Bank Reconciliation ToolMatch book and bank transactions, list outstanding checks and deposits, reconcile the balance.Pareto Analysis Tool (80/20)Paste categories and values to get a sorted Pareto chart, cumulative %, and the vital few.Expense TrackerLog expenses by category and date, see monthly totals and charts, import or export CSV.Financial Health Score CalculatorScore your finances out of 100 and get a prioritized to-do list for savings, debt and more.