Mycelocity
Biology decides whether you can grow mushrooms. Economics decides whether you should — at least as a business. This guide walks the chain that turns yield and cost into the numbers an owner or lender actually asks about: margin, break-even, and return on investment. Each step has a calculator behind it, and they all share one grow profile.
Step 1 — Contribution margin per block
Margin is what one block contributes after its own variable cost:
revenue = yield_lb × price · margin = revenue − COGS
This is the heart of the Profit per Block calculator. Yield comes from biological efficiency, COGS from Costing a Block. If margin per block is negative, no amount of volume saves you — that is the first thing to fix.
Step 2 — Break-even volume
Fixed costs — rent, salaries, insurance — do not care how many blocks you sell. Break-even is the volume at which contribution margin finally covers them:
breakevenBlocks = fixedCosts / marginPerBlock
The Break-even calculator returns this in both blocks and pounds per month. Below it you lose money; above it each additional block is profit. It is the most honest one-line summary of whether your price and cost structure work.
Step 3 — Monthly net profit
Scale margin by your monthly volume and subtract fixed costs:
monthlyNet = marginPerBlock × blocksPerMonth − fixedCosts
This is the figure that flows into the investment view — and the reason a small change in margin per block, multiplied across thousands of blocks, moves the whole business.
Step 4 — Payback and ROI
A profitable month does not by itself justify the capital it took to get there. Two calculators close the loop:
- Startup Cost totals the capital to open the doors — equipment, initial inventory, deposit, licensing, build-out.
- Payback & ROI divides that capital by monthly net profit to get payback months, then annualises it into a return on investment.
paybackMonths = capital / monthlyNet · ROI% = (monthlyNet × 12 / capital) × 100
Reading it as one model
The point of Mycelocity is that these are not four separate spreadsheets. Change your biological efficiency and the yield moves, which moves margin, which moves break-even, which moves payback — all from one grow profile. Use this chain to ask “what if”: what if price drops 10%? what if I halve contamination? what if rent doubles? The connected calculators answer instantly, so you can find the fragile assumptions before they find you.