Operations & inventory

MarginMaster

An offline profit and margin manager for e-commerce sellers.

Windows desktop app (.exe) US$20 · one-time

MarginMaster is an offline desktop app for e-commerce sellers who want to know the true profit on what they sell. Its Profit Calculator computes a live breakdown for any product or ad-hoc figures: revenue, every cost line (unit cost, shipping, platform fee, other), net profit per unit, gross margin, markup, and the break-even units needed to hit a target monthly profit. Edit any field and the panel recalculates instantly.

Alongside the calculator, a Dashboard shows your store's profitability at a glance, a Products catalogue tracks costs and margin per item, and a Sales log records orders across channels like Etsy, Shopify, eBay, Amazon and Direct. Everything runs on your own machine, with CSV and per-product PDF exports. No accounts, no cloud, no tracking.

What it does

  • Profit Calculator with a live breakdown: net profit per unit, gross margin, markup, and break-even units for a target monthly profit
  • Dashboard with net profit this month, average gross margin, units sold, best product, a 6-month profit bar chart, and profit-by-channel
  • Products catalogue tracking unit cost, sell price, shipping, platform fee and other costs, with a live margin column and a Healthy/Thin/Break-even/Loss health band
  • Sales log across channels (Etsy, Shopify, eBay, Amazon, Direct) that auto-fills price and fee from the chosen product and shows realised net profit
  • Editable product categories and sales channels, with removed options never rewriting records that already use them
  • CSV export for products and the full sales log, plus a branded per-product PDF profit report; all data stored locally on your machine
US$20 one-time payment · yours to keep forever · Windows desktop app (.exe)
  • 14-day refund if it doesn't work as described — Refund Policy
  • Instant download, delivered by email — re-download anytime from your receipt
  • No subscription, no account — works fully offline
  • No activation server — the app keeps working even if this website disappears
Works on
Windows 10 & 11 (64-bit)
Download
~125 MB · MarginMaster-win64.zip
Installs
On computers you personally own or control (EULA)
Updates
Free fixes and improvements for the version you buy — notices by email, never by the app phoning home

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Safe to download & install

A genuine, local-first desktop app — no telemetry, no account. Because we're a new independent maker, Windows may show a one-time SmartScreen prompt on first run; just click More info → Run anyway. Your download lists a SHA-256 checksum so you can verify it's authentic and untampered. How to install & verify →

SHA-256 · MarginMaster-win64.zipc54dfff6904ee4b82137ee6f18fb8a7229bb560523631f2cd36aba35cc27b38a