Unit Economics Calculator

Most UK D2C brands are optimising to the wrong number. They religiously track ROAS, use PMax as a catch-all and watch dashboards glow green whilst your margin compresses and cash flow tightens. This free calculator maps every cost layer between a sale and a pound of real profit, so you know exactly where your money goes and what your platform targets needs to align to.

What the Calculator CoversFull P&L Waterfall
Gross Revenue to CM1 to CM2 to CM3 to Net Profit, line by line
Breakeven ROAS Targets
Calculated at CM1, CM2 and CM3 levels, not just a blended guess
Return Rate & BNPL Impact
Model how returns and BNPL adoption erode your real net revenue
Sensitivity Chart
Visualise profit at every volume level and spot your breakeven units instantly

Who This Is For

This tool is designed for UK D2C founders, CMOs, heads of growth, and e-commerce finance leads who need to pressure-test their unit economics before scaling ad spend. It's particularly useful if you're:

Sense-checking whether the ROAS targets set in Google Ads or Meta actually reflect your margin structure, rather than platform defaults or last quarter's gut feel
Running contribution margin reviews and need a single source of truth across COGS, fulfilment, returns and marketing
Modelling the impact of a pricing change, discount promotion, or new fulfilment partner
Preparing investor materials and need a defensible unit economics model

  Kiezo Growth — UK D2C Unit Economics Calculator v2.0
Net revenue
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Gross profit (CM1)
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Variable profit (CM3)
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Net profit (pre-tax)
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Sold
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Kept
—
Returned
—
BNPL units
—
Disc. AOV
Inputs v2.0 — all values VAT-exclusive
Volume & pricing
Units sold
Full price AOV (£)
Discount (%)
Transactions
Return rate (%)
BNPL adoption (%)
Variable costs
COGS (%)
Shipping (£/unit dispatched) + forecast % adj

        
        
        
      
Warehouse & fulfillment (£/month) — enter only costs attributable to this SKU/range
Transaction fees (%)
BNPL fee (%)
Returns handling (£/return)
Write-Off % of Returned Units (COGS Written Off)
Marketing
Marketing & sales spend (£)
Fixed costs
Fixed overhead allocation (£) — enter only costs attributable to this SKU/range. Leave at 0 to evaluate on contribution margin only.
Revenue
Gross revenue (post-discount)—
(−) Returned revenue—
Net revenue—100%
CM1 — Gross profit
(−) COGS——
Gross profit——
CM2 — Contribution margin
(−) Shipping — £/unit × units dispatched——
(−) Transaction fees——
(−) BNPL fees——
(−) Returns handling — £/return × returns——
(−) Write-off — % of returned units' COGS——
(−) Warehouse & fulfillment — flat monthly——
Total contribution (CM2)——
CM3 — Variable profit
(−) Marketing & sales——
CM3 variable profit——
Fixed costs
(−) Fixed overhead allocation——
Net profit
Net profit (pre-tax)——
COGS / unit
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CM3 / kept unit
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Fixed cost / kept unit
—
Net profit / kept unit
—
Breakeven ROAS targets
COGS breakeven
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CM1 level
Contribution breakeven
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CM2 level
Variable breakeven
—
CM3 level

    Sensitivity — Units Sold vs Net Revenue, Variable Profit & Net Profit
    X-axis scales to 3× current units · hover to inspect
  

      
        
          
          
        
        
          
          
        
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
      
        
        
        
        
        
        
      
      
    Net revenue
Variable profit (CM3)
Net profit (pre-tax)
Breakeven (£0)
● current position
Built by Kiezo Growth · kiezogrowth.com

Understanding Your Three Margin Layers

UK D2C brands operate across three distinct profit levels, each with its own breakeven thresholds. Confusing them is one of the most common and costly mistakes in performance marketing (or not knowing them at all):

CM1 (Gross Profit): Net revenue minus COGS. Your gross margin percentage. This is the ceiling; every other cost comes out of here.
CM2 (Contribution Margin): CM1 minus all variable fulfilment costs: shipping, transaction fees, BNPL fees, returns handling, write-offs and warehousing. This is the margin your marketing budget is actually competing with.
CM3 (Variable Profit): CM2 minus your marketing and sales spend. If CM3 is negative at your current ROAS, you are destroying margin on every order, regardless of what your agency's dashboard shows.

The breakeven ROAS calculator outputs a target at each of these three levels, giving you a clear guardrail for how hard you can push acquisition without going underwater.

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