Contributing Writer, Business & Finance, updated June 26, 2026
The Short Answer
The estimate starts from published benchmark premium data for a 40-year-old buying a silver plan, then adjusts for age using the ACA's 3:1 age rating rule, scales for household size, multiplies by a state cost factor, and adjusts up or down based on plan tier. The result is an unsubsidized premium, which is what you would pay without a premium tax credit.
Understanding the Metal Tiers
ACA plans are sorted into four tiers based on how costs are split between you and the insurer on average. Bronze plans carry the lowest monthly premium but the highest deductibles and out-of-pocket maximums, and work best for people who rarely use medical care. Silver plans sit in the middle on premium cost and are the only tier eligible for cost-sharing reduction (CSR) subsidies. According to KFF, silver is the most commonly selected tier on the marketplace. Gold plans charge higher premiums but lower your costs when you actually use care, and tend to pencil out for people who expect frequent visits or prescriptions. Platinum plans have the highest premiums but the lowest cost-sharing, and are a narrow fit not available in all states.
What the Estimate Does Not Include
Premium is only part of your health coverage cost. Deductibles, copays, coinsurance, and out-of-pocket maximums matter a great deal for your total spending. A bronze plan might cost $150 less per month but carry a $7,000 deductible, so your break-even point depends on how much care you actually use. The estimate here covers premium only.
How Age Affects the Cost
Under ACA rules, insurers can charge older enrollees up to three times what they charge a 21-year-old for the same plan, the steepest age adjustment the law allows. In practice, a 60-year-old often pays two to three times more per month than a 30-year-old buying the same silver plan in the same state. This calculator applies that age curve to the benchmark rate.
Calculator methodologyHealth Insurance Reference Data
The age-rating curve and baseline this calculator runs is documented in full, alongside eight other tools, on the 2026 Insurance Needs Formulas Reference.
| Component | How it prices |
|---|---|
| Site baseline (age 40) | $477/mo |
| Age curve | ACA 3:1 ratio × household factor × state factor × plan-tier factor |
| Default profile result | $5,724/yr ($477.00/mo) |
Default profile: age 40, household of 1, standard state and plan tier. This site's baseline is its own model, distinct from KFF's $625/mo national benchmark cited in the FAQ below; full methodology and the CSV are on the reference page above.