GROSS. — free commercial calculators for UK FMCG brand teams

The Payback

How much incremental volume a promotion needs to pay itself back. Trade spend ROI and break-even in cases for any UK FMCG promo mechanic.

How much incremental volume a promo needs to pay itself back. Break-even in cases, and the uplift that implies on your base.

The workings

Every promo is a loan you make to your own volume. The investment goes out; the payback arrives, or does not, as incremental margin on incremental units. This page divides one by the other and tells you the volume the promo has to shift before it has paid for itself.

The margin used for payback is contribution after landed cost during the promo — not your everyday margin, because during the deal you are usually funding a price cut too. Uplift assumptions are the soft spot: a buyer's uplift forecast is a sales aid, not a measurement. If the payback only works at the top of the uplift range, it does not work.

The rule of thumb the trade actually uses: if a promo cannot pay back inside the deal period plus one buying cycle, it is brand investment, and brand investment should be a decision, not an accident.

The other calculators

• Home — Free commercial calculators for UK FMCG brand teams. Retailer margins, gross-to-net, trade spend payback, supp
• The Shelf — Your range, defined once. Enter each product’s cost price, RSP, units per case and rate of sale — every calcul
• The P&L — See what the retailer really makes on you. Reads top-down: shelf price, VAT, who takes what, and what you actu
• The Waterfall — Every deduction between the shelf price and your bank. Gross to net net, with promo funding, back margin and o
• The Floor — The lowest cost price, or the RRP, that still clears your target margin. Solved backwards from the number you
• The Listing — Model the range review before the buyer does. Week by week, with a full promo calendar behind the annual GSV-t
• The Stock Answer — What to order, and when, before you run out. A weekly supply plan that follows your promo calendar, in whole c
• The Amazon Cut — What FBA takes before you see a penny. Every fee per unit, plus a full-year GSV-to-net P&L by cases sold.
• The TikTok Cut — What TikTok Shop takes on every sale. Every fee per unit, plus a full-year GSV-to-net P&L by cases sold.
• The Line-Up — The same product across grocery, Amazon and TikTok, side by side. The biggest channel is rarely the one that p
• The Range — The whole portfolio on one till roll. Blended margin, the SKU that carries the range, and the full-year plan.
• The Wait — Margin is an opinion; cash is a fact. When the money actually moves — and the gap your bank account has to sur
• The Ledger — One email a month on the commercial maths of UK FMCG. No selling. The archive lives here.
• The Ledger No. 001 — Your margin is your insurance. The minimum margin that survives a halved rate of sale, worked in full.
• The Guides — The long reads behind the calculators: retailer margin, gross-to-net, FBA fees and margin benchmarks, written
• How retailer margin actually works — Front margin, back margin, margin vs mark-up and the wholesaler layer — with the arithmetic shown.
• Gross-to-net: where your revenue goes — GSV, NSV, promo funding and back margin — the waterfall between invoice and bank, and what a healthy one looks
• Amazon FBA fees in the UK — Referral, fulfilment, storage and the plan, added up honestly — plus the break-even price nobody checks.
• FMCG margin benchmarks — Indicative UK brand gross-margin ranges by category, measured on the right base and honest about being ranges.
• Payment terms in UK grocery — Sixty days is not a detail — it is working capital, and it is yours. The debtor-day maths, the shelf-fill trap
• What a promotion actually costs — Funding off invoice, the uplift with the widest error bars in the building, and the payback test nobody runs.
• The Rate Card — Every default in GROSS., what it is, when it was checked and where it comes from. The maths is only as good as

Free, no sign-up. The maths is checked; the defaults are dated and sourced on The Rate Card. VAT number: not applicable. This is a website.