GrowMargin
Everything you get

A profit tool built around how sellers actually work.

GrowMargin is not a generic calculator. Every feature exists because a seller needed a clear, honest answer — without needing to be a financial analyst to understand it.

The problem

Most sellers don't know their real profit.

Platform fees are buried in help docs. Spreadsheets take hours to set up and break when fees change. Free online calculators give you a number with no context. None of them tell you whether that number is good or bad.

Platform fees change quietly

Etsy, Shopify, and Amazon update their fee structures. Most sellers find out when their profits drop — not before.

Gut-feel pricing is a gamble

Pricing based on what feels right ignores compounding costs: transaction fees, processing fees, shipping, and ad spend all eat into your margin simultaneously.

A number without context is useless

Knowing you made $8 on a $40 product means nothing unless you know whether 20% margin is healthy, dangerous, or average for your category.

Core features

What GrowMargin does for you.

Live profit calculations

Your profit, margin, and full fee breakdown update with every keystroke. No submit button. No page reload. Change your selling price by $1 and see exactly how your margin shifts in real time.

  • Profit per sale, updated instantly
  • Margin percentage with visual indicator
  • Full fee breakdown — every line itemised
  • Total cost stack visible at a glance
Selling price$45.00
Product cost$12.00
Shopify fee (2.9%)−$1.31
Processing fee ($0.30)−$0.30
Shipping−$4.00
Your profit+$27.39
60.9% margin — strong

Shopify

Payment processing · Transaction fee · Shipping

Etsy

Transaction fee · Listing fee · Payment processing

Amazon FBA

Referral fee · FBA fulfilment · Ad spend

Platform fees pre-loaded, fully adjustable

Standard fees for Shopify and Etsy are pre-loaded and cover most sellers out of the box. Amazon FBA fees vary by product category and size, so we pre-fill a common starting point — you adjust the referral fee and fulfilment fee to your specific product.

Every fee field is editable. Different Shopify plan, different country Etsy rates, specific Amazon category — override any default to match your exact situation.

Plain-language insights

After calculating, GrowMargin reads your numbers and tells you what they mean in plain English. Not just the figure — the interpretation. Is this a healthy margin? Are you pricing yourself out of profit? Should you raise your price before running ads?

Insights adapt to your actual numbers. A 10% margin on a $200 product triggers different guidance than a 10% margin on a $15 product.

Strong margin. You have room to grow confidently.
Tight margin. Consider raising your price before running ads.
You're losing money at this price. Try raising it or cutting costs.

Saved calculations

Blue ceramic mug

Etsy

$11.40

28% margin

Linen tote bag

Shopify

$18.70

42% margin

Scented candle set

Amazon FBA

$6.20

19% margin

Save scenarios and compare

Save any calculation with a name and come back to it later. Compare your best-selling products side by side to see which ones are actually worth scaling — and which ones are quietly draining your margin.

Basic plan saves up to 10 calculations. Pro gives you up to 25 saves.

Branded PDF exports

Export any calculation as a clean, professional PDF report. Add your business name and logo in settings and it appears on every export automatically.

  • Clean, professional layout
  • Your business name and logo included
  • Full fee breakdown on every export
  • Useful for supplier meetings, records, or business partners
BL

Bloom & Co.

Shopify Profit Report

Blue Ceramic Mug — 500ml

Selling price$45.00
Product cost$12.00
Total fees$5.61
Net profit$27.39
Pro plan

For sellers ready to run ads.

The Pro plan adds tools for the next stage: understanding whether your margins can support advertising spend.

ROAS & break-even projections

ROAS — Return on Ad Spend — tells you the minimum your ads need to return for you to stay profitable. GrowMargin Pro calculates your break-even ROAS automatically, so you can set realistic targets before spending a dollar.

  • Break-even ROAS calculated from your real margins
  • Maximum cost-per-acquisition (max CPA)
  • 30-day revenue and profit forecast at scale

Email profit reports

Send any calculation directly to your inbox as a formatted report. Useful for reviewing your numbers weekly, sharing with a co-founder or accountant, or just keeping a paper trail without managing files.

  • Send to any email address
  • Full breakdown included
  • Useful for weekly reviews and sharing
Compare calculations

Stop guessing. Compare.

Save different pricing scenarios, then put any two side by side. See exactly what changes — and which one actually makes you more money.

BASIC

Side-by-side view

Select any two saved calculations and see them next to each other — selling price, product cost, platform fees, total costs, profit, and margin. No more switching tabs or scrolling back and forth.

  • Works across platforms — compare Shopify vs Etsy
  • Compare different price points on the same product
  • Compare same product with different cost structures
PRO

% change analysis + outcome

Pro adds a third column showing how each metric changed as a percentage — and a clear outcome summary at the bottom telling you which scenario wins and by exactly how much.

  • Per-metric % change (profit up 38%, margin up 18%…)
  • Green for improvements, red for increases in cost
  • Outcome summary: "Scenario B earns 38.4% more profit"
Platform coverage

Three platforms. One tool.

Shopify, Etsy, and Amazon FBA all have completely different fee structures. GrowMargin handles all three, with platform-specific fields for each.

Shopify

Covers Shopify Payments processing fees (percentage + fixed), transaction fees, shipping, product cost, and ad spend. Adjustable for different Shopify plan tiers.

  • Shopify Payments fee
  • Per-transaction fixed fee
  • Shipping cost
  • Ad spend (optional)

Etsy

Covers Etsy's transaction fee (6.5% of sale + shipping), listing fee, and Etsy Payments processing fee. All adjustable by country.

  • Transaction fee (6.5%)
  • Listing fee ($0.20)
  • Payment processing fee
  • Shipping cost

Amazon FBA

Covers Amazon's referral fee (percentage of sale price, varies by category) and the FBA fulfilment fee (based on product size and weight).

  • Referral fee (15% default)
  • FBA fulfilment fee
  • Ad spend (optional)
  • Product cost
Built differently

A few things we deliberately avoided.

No subscriptions

Both plans are a single one-time payment. Your access never expires and we never charge you again.

Any currency

Set any currency symbol and the calculations work identically. The fee percentages are currency-neutral.

Your data is private

Saved calculations are stored against your account only. We don't sell data and don't have ads.

No jargon

Every label, insight, and piece of guidance is written for someone who has never used accounting software.

Fee data maintained

When platform fee structures change, we update the presets. You don't need to track this yourself.

Mobile-first

The calculators are fully usable on a phone. No horizontal scrolling, no pinching. Built for wherever you work.

Simple pricing. No surprises.

Pick the plan that fits where you are today. You can upgrade later and only pay the difference.

Basic

Everything you need to understand your profit.

$15one-time
  • Measure profit across major online seller platforms like Shopify, Etsy and Amazon
  • Live profit calculations with beginner insights
  • Save up to 10 calculations
  • Compare any 2 saved calculations side by side
  • PDF profit exports
  • Currency customisation
Best Value

Pro

For sellers ready to scale with confidence.

$29one-time
  • Everything in Basic
  • Compare calculations with % change per metric
  • Overall profit outcome — which scenario wins and by how much
  • Marketing projections & break-even ROAS
  • Email profit reports (send to your inbox)
  • Save up to 25 calculations
  • Priority access to new features

Already on BASIC? Upgrade to PRO — pay only the difference ($29 − $15 + $5 processing fee = $19 total)

Ready to know your real profit?

One-time payment from $15. No subscription. Takes minutes to set up.