The Unit Economics Calculator: Building a Profitable LED Therapy Brand from Scratch
The Components of Landed Cost
Before you can calculate margin, you need to understand the full cost of getting a product from the factory to your customer. Here’s every cost component:
Manufacturing costs (per unit):
- Factory unit cost: the price you pay per unit from the OEM/ODM
- Packaging materials: outer box, protective inserts, instruction manual, warranty card
- Accessories: charging cable, carrying case, any bundled accessories
- FOB price includes factory costs and getting goods to port
- Ocean freight: container cost divided by number of units per container
- Port handling and terminal charges
- Customs duties and brokerage fees
- Inland freight: port to your warehouse
- Last-mile delivery: warehouse to customer (if FBA or direct fulfillment)
- Pick and pack fee (warehouse or 3PL)
- Storage fees (monthly cost per unit stored, prorated)
- Return processing fee (for returned units)
- Payment processing fee (typically 2.9% + $0.30 per transaction for card payments)
- Platform fee (Amazon referral fee, Etsy listing fee, Shopify transaction fee)
- Advertising cost per unit sold (your ACoS × average order value)
- Marketing spend attributed to each unit (difficult to calculate precisely)
- Organic customer acquisition cost (estimated)
- Warehousing overhead (rent, labor, systems)
- Insurance on inventory
- Cost of capital tied up in inventory (opportunity cost)
- Container: $3,200
- Per unit: $1.14
- Duties (25% tariff on $25 unit cost): $6.25
- Port and broker: $0.40
- Inland freight: $0.50
- Total shipping per unit: $8.29
- Amazon: 15% referral + $1.80 fulfillment = ~18% of selling price
- Wholesale to distributor: typically 10% payment processing only
- DTC: 2.9% + $0.30 transaction fee
- Maximum total cost: $79 × 0.45 = $35.55
- If shipping and fulfillment costs are $12 per unit, maximum manufacturing cost: $23.55
- Gross margin by SKU (manufacturing + shipping vs. revenue)
- Net margin by SKU (after all fulfillment, transaction, and advertising costs)
- Inventory days on hand (days of inventory remaining at current sales rate)
- Cash conversion cycle (days from paying supplier to collecting from customer)
- ACoS by product and by channel
- Return rate by product
Shipping costs (per unit):
Fulfillment costs (per unit):
Transaction costs (per unit):
Customer acquisition ( amortized):
Other costs (amortized):
The Model in Practice: Building the Unit Economics Spreadsheet
Here’s how to build a unit economics model for an LED therapy brand. Use a spreadsheet; don’t try to do this in your head.
Column 1: Unit selling price
Set different scenarios: wholesale price, MSRP, Amazon price, DTC price.
Column 2: Unit manufacturing cost
Start with factory price + packaging + accessories.
Column 3: Shipping per unit
Calculate: (container cost ÷ units per container) + duties + port fees + inland freight
For a 40-foot container from Shenzhen to West Coast US with 2,800 units:
Column 4: Gross margin per unit
Selling price – manufacturing cost – shipping cost
Column 5: Platform fees
Column 6: Advertising cost
Track your actual ACoS over trailing 90 days. Apply to each selling price.
Column 7: Return rate cost
Return rate × unit cost of handling returns (including replacement cost and shipping)
Column 8: Net margin per unit
All revenue minus all costs, per unit
Column 9: Working capital cost
Units in pipeline × unit cost × months in pipeline × cost of capital rate
If you have 3 months of inventory on hand at any time, at $25 unit cost, at 10% annual cost of capital: 3 months × (10%/12) × $25 = $0.625 per unit
The Break-Even Points That Matter
Once you have the model built, these are the questions it should answer:
What’s your minimum viable wholesale price? For a given retail price point, what’s the maximum you can pay for manufacturing + shipping and still hit your gross margin target (typically 50%+ for consumer brands)?
Example: Target retail price $79, target gross margin 55%
What’s your Amazon break-even ACoS? At your current selling price and unit economics, what’s the maximum advertising cost per sale that still leaves you profitable?
What’s your minimum order quantity ROI? As order size increases, per-unit manufacturing cost typically decreases. At what order size does the cost reduction justify the additional working capital tied up?
The Price Setting Framework
For LED therapy devices, we use a three-tier pricing structure:
MSRP (Manufacturer’s Suggested Retail Price): The price that creates perceived value and supports retail channel margins. Typically set at 2.5-3.0× your landed cost.
Wholesale price: The price you offer to distributors and retailers. Typically 40-50% off MSRP (meaning 55% margin for the retailer). This means your wholesale price should be approximately 1.2-1.5× your landed cost.
DTC price: Your direct-to-consumer price on your own website. Typically equal to or slightly below MSRP.
Amazon price: This is set by the market, not by you. If your landed cost doesn’t support competitive Amazon pricing while maintaining profitability, don’t sell on Amazon.
The Scenario Analysis That Prevents Bad Decisions
Before committing to any new product, run these scenarios through your model:
Optimistic scenario: Best-case pricing, lowest shipping rates, no damage returns.
Base scenario: Expected pricing, standard shipping rates, average return rate.
Pessimistic scenario: Competitive pricing pressure, peak shipping rates, high return rate.
If the pessimistic scenario still generates positive gross margin, the product is worth pursuing. If the base scenario generates marginal returns, proceed with caution. If the base scenario generates negative margin, walk away.
The question to ask before any new product launch: “What needs to be true for this product to be profitable?” If you can’t identify the specific conditions that would make it profitable, and you can’t reliably create those conditions, don’t launch the product.
The Metrics to Track Monthly
These six metrics, tracked monthly, give you a clear picture of whether your business is economically sustainable.
The Common Mistakes the Model Would Have Prevented
Mistake 1: Setting price based on competitor prices. If your landed cost is $40 and competitors are selling at $65, your answer is not “lower our margin and sell at $65.” Your answer is “reduce our landed cost to $28 or don’t enter that market segment.”
Mistake 2: Ignoring working capital costs. A product with 20% gross margin might look profitable. If it requires 6 months of inventory on hand, and your cost of capital is 12%, the real margin is closer to 14%. The model catches this.
Mistake 3: Pricing before knowing landed cost. We did this. Set MSRP before getting a real manufacturing quote, then negotiated a factory price that left us underwater. Know your landed cost before you announce pricing.
Mistake 4: Mixing up gross margin and net margin. A 60% gross margin on a product looks great until you subtract $18 Amazon fees + $12 advertising + $2.50 returns, leaving you with 15% net margin. Track both.
Build the model. Run the numbers. Every new product decision should go through this process before you commit inventory capital.
The brands that fail usually aren’t bad at marketing or sales — they’re bad at math. The model prevents that.