Boutique calculator methodology
Every Grow Your Boutique calculator uses published formulas with inputs the user controls. Nothing is weighted by a hidden score and no result is generated by a model. This page documents the math so instructors, advisors and writers can check it before citing a figure — and so you can reproduce any result by hand.
Results are planning estimates for retail decision-making, not accounting output or financial advice.
Break-even orders and revenue
How many orders a month does a boutique need before it stops losing money?
Formula
contribution per order = (AOV × gross margin %) − (AOV × fee %) − shipping and packaging per order
break-even orders = monthly fixed expenses ÷ contribution per order
break-even revenue = break-even orders × AOV
orders for a profit goal = (fixed expenses + desired profit) ÷ contribution per orderInputs
- Monthly fixed expenses — costs incurred whether or not anything sells.
- Average order value (AOV).
- Gross margin percentage — revenue left after product cost.
- Platform and payment processing fees as a percentage of order value.
- Shipping and packaging carried per order.
Assumptions
- Gross margin is treated as constant across the order mix.
- Fixed costs are genuinely fixed within the period modeled.
- Returns, discounts and shrink are not modeled separately — lower the margin input to account for them.
Limits: Contribution per order at or below zero means no order volume reaches break-even; the model reports that rather than a number.
Product profit, margin and markup
Does a single product make money at its current price?
Formula
final price = selling price × (1 − discount %)
payment fee = final price × processing % + flat fee
total cost = product + shipping + packaging + ads + other + payment fee
profit = final price − total cost
margin % = profit ÷ final price × 100
markup % = profit ÷ product cost × 100
break-even price = (non-fee costs + flat fee) ÷ (1 − processing %)
price for a target margin m = (non-fee costs + flat fee) ÷ (1 − processing % − m)Inputs
- Selling price and any discount applied.
- Product, shipping, packaging, advertising and other per-unit costs.
- Payment processing percentage and flat per-transaction fee.
Assumptions
- Margin is calculated on retail price; markup is calculated on product cost. They are not interchangeable.
- One unit per transaction, so the flat fee is charged once.
- Overhead not entered as a per-unit cost is excluded — use the break-even calculator for fixed costs.
Limits: A target margin at or above (1 − processing %) has no solution; the model reports the price as unreachable instead of returning a misleading figure.
Pop-up and event profit
What does a market, pop-up or vendor event have to sell to pay for itself?
Formula
total event cost = booth fee + travel + lodging + labor + other
break-even sales = total event cost ÷ gross margin rate
break-even transactions = ceiling(break-even sales ÷ AOV)
projected gross profit = projected sales × gross margin rate
projected profit or loss = projected gross profit − total event costInputs
- Event costs: booth fee, travel, lodging, staff pay, and anything else event-specific.
- Average order value and gross margin percentage.
- Optionally a sales projection, transaction count, or foot traffic with a close rate.
Assumptions
- Only event-specific costs are counted; year-round overhead sits outside the event decision.
- Unsold inventory retains its value and is not expensed to the event.
- Transactions are rounded up — a partial sale is not a sale.
Limits: Projections come only from figures the user enters. The tool does not supply benchmark conversion rates or predict attendance.
Inventory turnover and days inventory held
How many times does a boutique sell through its average inventory?
Formula
average inventory = (beginning inventory + ending inventory) ÷ 2
inventory turnover = COGS ÷ average inventory
days inventory held = days in period ÷ inventory turnoverInputs
- Cost of goods sold for the period.
- Beginning and ending inventory, both valued at cost.
- Number of days the period covers.
Assumptions
- Both inventory figures use cost, not retail value. Mixing the two inflates turnover.
- A two-point average approximates a period average; seasonal boutiques should run shorter periods.
Limits: Average inventory of zero makes turnover unmeasurable, and zero COGS returns zero turnover. Both cases are labeled rather than hidden.
Traffic needed for a revenue goal
How many sessions does a revenue goal require?
Formula
orders needed = ceiling(revenue goal ÷ AOV)
sessions needed = ceiling(orders needed ÷ (conversion rate ÷ 100))
daily sessions = sessions needed ÷ days in period
traffic gap = sessions needed − current sessionsInputs
- Revenue goal and the number of days it covers.
- Average order value.
- Planning conversion rate as a percentage.
- Optionally, current sessions for a comparable period.
Assumptions
- Conversion rate and AOV hold steady as traffic grows, which is a planning simplification.
- Every order is a first-time purchase; repeat customers are not modeled separately.
Limits: This sizes the traffic requirement. It makes no claim that the requirement is achievable with a given budget or channel.
Citing these calculators
Cite as: Hatton, C. "Boutique calculator methodology." Grow Your Boutique. https://growyourboutique.com/boutique-calculator-methodology. Educators and advisors can embed the tools free of charge — see calculator embeds and resources for educators.