The calculator projects a monthly business using the assumptions you enter. It does not call an AI model, inspect your account, or predict customer behavior. Prices are in USD. Taxes, annual contracts, enterprise discounts, shared credits, and costs you do not enter are excluded.
Start with people, not requests
Active users are divided into paying and free users. Paying users are divided into normal and heavy users. Heavy and free usage multipliers apply to the activity you specify for a normal paying user. Cohort counts are expected values; fractional counts are retained during calculation rather than rounded early.
For 2,000 active users with 50% paying and 10% of paying users classified as heavy, the calculator uses 900 normal paying, 100 heavy paying, and 1,000 free users. A heavy multiplier of five means five times the normal activity. A free multiplier of 0.1 means 10% of normal activity.
Account for every billed component
Each model stage or tool can be a separate component. For text, the calculator multiplies disjoint uncached-input, cache-read, cache-write, and billed-output token counts by their rates. Billed output should include reasoning when your provider charges for it. Add system prompts, tool schemas, tool results, and accumulated context to the appropriate counts.
Image, speech, video, and custom components use their explicitly labeled units. Token-priced image usage is an estimate unless you enter measured usage; a fixed resolution alone does not establish its token cost. Cached storage uses retained tokens multiplied by storage hours and is a monthly per-active-user allocation, independent of heavy/free activity.
Additional billable attempts are a percentage of extra charged usage. They are not a claim that every failed request is billed. Put only charged generated video seconds in a video component.
Revenue and contribution
Revenue = paying customers × monthly price
Fees = paying customers × (price × percentage fee + fixed fee × transactions)
Contribution = revenue − AI costs − other variable costs − payment fees
Contribution margin = contribution / revenue
Monthly profit = contribution − fixed operating costs
Contribution margin is before fixed costs. If revenue is zero, margin is undefined; expenditure and loss remain calculable. Other variable costs are entered per active user. Payment fees are excluded until you choose to include your own fees.
Find a price floor
Let W be variable costs per paying customer, including the free-user subsidy at your conversion ratio. Let g be your target margin, p your percentage payment fee, f your fixed payment fee, and t the number of transactions per paying user.
Required monthly price = (W + f × t) / (1 − p − g)
The result is rounded up to the next cent. A nonpositive denominator means the requested margin cannot be achieved under those assumptions. With no paying-customer conversion, there is no price floor for that business model.
Break-even and growth
Contribution per paying customer = price × (1 − p) − f × t − W
Break-even paying customers = ceil(fixed costs / contribution per paying customer)
If contribution per paying customer is nonpositive, there is no finite break-even. The growth chart holds conversion, cohort mix, unit costs, and usage constant. It is an arithmetic projection, not a growth forecast. Volume discounts, infrastructure capacity steps, or changing usage need separate scenarios.
A reproducible worked example
Use synthetic rates of $2 per million input tokens and $10 per million output tokens. One action uses 2,000 input and 500 output tokens: $0.004 + $0.005 = $0.009.
Assume 100 actions per normal user per month, 1,000 paying users, 1,000 free users, 10% heavy paying users at five times usage, and free usage at 10%. Charge $19 per month. Include a 3% plus $0.30 payment fee, one transaction monthly, and $50 fixed costs.
| Result | Calculation |
|---|---|
| Normal user AI cost | $0.90/month |
| Heavy user AI cost | $4.50/month |
| Free user AI cost | $0.09/month |
| Total AI cost | $1,350/month |
| Revenue | $19,000/month |
| Payment fees | $870/month |
| Contribution margin | 88.315789…% |
| Profit after fixed costs | $16,730/month |
| Price for a 70% margin | $6.12/month |
| Break-even | 3 paying customers at the same conversion ratio |
These rates are test fixtures, not a quotation for a particular model.
Precision, pricing, and privacy
Calculations use decimal arithmetic with 40 significant digits. Money is rounded for display, not before multiplying usage. Small costs remain visible. Charts use floating-point coordinates only after financial calculations have completed.
Rates come from a versioned, reviewed catalog. Saved and shared scenarios preserve their snapshots. Choose “Review current prices” to see and explicitly apply changes. Imported and shared rates are user-supplied, even when their labels resemble official profiles.
Everything runs locally after static assets load. A share link contains its scenario in the fragment. It is not encrypted: anyone receiving it can read the assumptions. Read the privacy policy or inspect pricing sources.