How to Use This Tool
Solve price from costs and contribution target instead of marking up one cost line. Calculate minimum sustainable price, break-even price and contribution per unit from variable, fixed, volume and payment assumptions.
The decision this tool supports
A markup on variable cost can leave fixed overhead and percentage fees unfunded even while each sale looks profitable. This page keeps the decision bounded to minimum sustainable price and the supporting outputs shown beside it. Sustainable Price does not import an account, infer a market rate, or silently substitute an industry average.
Inputs and units
The Sustainable Price calculation uses Variable cost per unit, Monthly fixed cost allocation, Expected monthly units, Target contribution margin, Payment fee rate. Keep all money values in one currency and all time, distance, mass, energy or volume entries in the unit printed beside the field. Mixing Sustainable Price scopes can produce a plausible number with the wrong meaning.
- Variable cost per unit is entered in currency.
- Monthly fixed cost allocation is entered in currency.
- Expected monthly units is entered in units.
- Target contribution margin is entered in % of price.
- Payment fee rate is entered in % of price.
Formula and worked check
Allocated cost per unit = variable cost + fixed cost ÷ units. Price = allocated cost ÷ (1 − target margin − payment fee rate). $18 variable cost plus $12 fixed allocation per unit, a 25% contribution target and 3% fee yields $41.67 sustainable price and $30.93 break-even price. The Sustainable Price default is an executable known-answer case, not a benchmark or recommendation. Change one input and verify that the direction of minimum sustainable price still matches the stated relationship.
How to interpret the result
The result is a modeled floor for the entered volume and allocation, not proof that customers will pay the price or that all overhead belongs to the product. The additional Sustainable Price outputs expose the denominator, comparison, capacity or reverse value needed to audit the primary result instead of presenting one unexplained number.
Assumptions
- Expected units are a realistic denominator for fixed-cost allocation.
- Margin and fee are percentages of selling price.
- Target margin plus fee must remain below 100%.
Save the Sustainable Price input values and date with any material decision. A later Sustainable Price rerun is reproducible only when the same assumptions and units are available.
Limitations and safety boundary
Taxes, tiered fees, refunds, channel commissions, discounts, capacity changes and demand response are not modeled. Sustainable Price is an estimate and cannot replace a contract, local code, licensed professional, calibrated measurement, lender statement or platform report where one governs the decision.
Source and privacy
The Sustainable Price definition or rule was checked against U.S. Small Business Administration — Manage your finances on 2026-08-26. Recheck U.S. Small Business Administration — Manage your finances when a specification or policy behind Sustainable Price can change. Sustainable Price arithmetic runs in this browser tab; ecech does not receive the values through a calculation API.
Sources & assumptions
Tool Spec v2 · verified 2026-08-26. Platform rules and fees can change; the editable inputs remain authoritative for your account.
Official references
- U.S. Small Business Administration — Manage your finances (checked 2026-08-26)
Model assumptions
- Expected units are a realistic denominator for fixed-cost allocation.
- Margin and fee are percentages of selling price.
- Target margin plus fee must remain below 100%.
- Taxes, tiered fees, refunds, channel commissions, discounts, capacity changes and demand response are not modeled.
