Sizemill

The book

Capital deployed by position

Below cost at bearThinStrong expected ROI

Tile area is landed cost, colour is probability-weighted ROI, the small figure is the market's last sale against your base. Click a tile to open the position.

Command list

Realised profit by month

Dashed line is your monthly target

Stock ageing

Days held, open positions

Market pulse

What you hold and what you watch, marked against the market this morning

Deal Lab simulated market data

Describe the item and the price you think it sells at. Sizemill pulls live and sold comps from four marketplaces, strips the fakes, and tells you whether your number is right before you spend a pound.

Style code works too: DH6927-111
Hurdles every deal is scored against. They are yours; a member's would be theirs.
Drops listings priced under 45% of the cleaned median, sellers under 10 feedback, and titles with replica language.
Press D anywhere to come here.

Underwrite a supplier list

Paste what a supplier sent you; every line is priced against the market and your mandate.
Name, size, price per line.
Nothing scanned yet. Try the three examples: , ,

Market simulated market data

Price history for anything in the catalogue. Pick a product and a window; the table shows how it has moved over every horizon at once.

Last sale, StockXGOAT30-day average

Change by horizon

Last sale then vs now

Verdict

Price construction

A mark should show its inputs

Normalised comp set

Size premium

Last sale by size against the product average

Where the data comes from

Watchlist simulated market data

Things you don't own yet. Set the price you'd buy at and Sizemill tells you the morning the market gets there.

Board memo

The board's review of the two builds, what it resolved, the roadmap, and — because it matters more than the ideas — which data feeds are real, which are restricted, and what they cost.

Two builds, one table

Board review of 6 September 2026. A is this build, B is the outside build.

Resolutions of the board

What changed in v3 because of the review

Data feeds, checked

Status as of September 2026. Verify before building; terms change.

Feature roadmap

Ranked by value to a reseller doing under 100 orders a month, which is most of the sector

Running cost at 10 members

What the board would ask

Positions

Every pair and piece you hold, priced three ways. Click a row to edit, drop in a photo, or mark it sold.

Add position

Type the price you paid and three prices you believe in. Everything else is computed as you type.

Your floor. If this is under cost, the tile turns red.
Used as the live mark on the tape.
The number you quote first.
Shortcut: N to come here, D for Deal Lab, ⌘⏎ to save. Or price it in Deal Lab first and it prefills everything.
Drop a photo hereor click to choose, or paste from clipboard

Scenarios

Weight how likely each outcome is and the whole book reprices: expected value, expected ROI, and the tax you would owe on it.

Probability weights

Bear
Base
Bull
Weights are normalised to 100 automatically. Your realised record suggests a calibration:

Book under each scenario

Open positions, net of fees and outbound shipping

Per position

Bars show where each scenario lands against landed cost

Tax engine

Profit is shown before and after tax everywhere in Sizemill. The rate moves by itself as your projected annual profit crosses a band.

Where you sit this year

Companies you control
Period monthsDividends received
Projected annual taxable profit
Defaults to realised year-to-date plus the probability-weighted value of open stock. Drag to test what-ifs; .

Tax reserve

Money you should not touch

Sizemill suggests moving the marginal rate of every realised profit into a separate pot on the day of sale. Shortfall is what you owe on this year's profit minus what is already set aside.

VAT radar

Rolling 12-month turnover

Threshold and the second-hand margin scheme are set in Settings. Check the current threshold with your accountant; it moves.

Bands in use

Cash rule per £1,000 realised

Reserve first, then reinvest

Capital efficiency

Velocity return on the open book

Cash unlock queue

What to sell first if you need buying power

Client desk

Every client as a book of its own: what they buy, how often, what they pay, what they owe, and the one thing worth doing today. Direct sales with a relationship behind them are the highest-margin channel you have.

Today

Gross profit by tier

Realised, all time

Invoices and money owed

Record payments as they land; the last one marks the stock sold

Sourcing requests

Every "can you get me…" message becomes a card. Move it right as you source, quote, buy and deliver. Margin is estimated before you spend a pound.

Connections

Where stock gets seen, sold and paid for. Every row says plainly whether it is live; the Test button talks to the real endpoint and reports what came back.

Daily brief

Effort this month

Progress to target

Sizemill for resellers

The same book, sold to other resellers and personal shoppers. Multi-workspace, benchmarked against the cohort, and white-label for agents who manage several players.

How you compare

Anonymised cohort, last 90 days (illustrative)

Benchmarks are the product. Nobody else can tell a reseller their ROI is in the 38th percentile for Jordan 4s and that their average days-to-sell is double the cohort.

Workspaces

Switch from the rail

Proposed pricing

Starting point, not a decision

Ledger

Every pound in and out, in order, and never edited. Cash on hand is the sum of this table, not a number you type. Mistakes are reversed with a new entry, so history stays true.

Analytics

Where the profit came from and where it didn't. Realised sales only; expectations live on the book.

Profit by brand

realised

Profit by channel

net of fees

Profit by client tier

who is worth the effort

Margin by month

realised profit as a share of revenue

Days to sell

realised, by brand

Pricing accuracy

where sales landed against your three prices

Size performance

realised profit and count by size

Network

Requests you can't fill matched to stock other members hold, and other members' requests matched to yours. Members stay anonymous until both sides accept; Sizemill takes a fee on the match.

Your requests, their stock

Fill an order without buying

Their requests, your stock

Demand you didn't have to find

How the network works

Automations

Rules that act, not just warn. Each one shows what it would do before it does it, and everything it does lands in the ledger.

Dry run

What the enabled automations would do right now

Data room

The raise, as a working model. Every number here is an assumption you can change; nothing is a claim about the market that hasn't been marked as one.

Revenue model

Three tiers, thirty-six months, logistic ramp to the member targets you set

Use of £5,000,000

Twenty-four months of runway to the Series A metrics

Milestones and what they unlock

Market, as assumptions

Change them; the sizing recomputes

Why this wins

Team to hire

Risks the board will raise

Product spec

Every feature in the product, in detail: what it is for, how it is computed, the data it needs, the feed it depends on, and where it stands. Open any card.

Settings and customise

Fee schedules, defaults, your own fields and columns, and the rules behind every alert. Every number here flows through the whole book.

Channel fees

Editable. Verify against each platform's current schedule.

Defaults

Customise the book

Your columns, your fields, your words

Your data

Saved to your account as you work and cached in this browser; the backup file is belt and braces.

Earlier versions

Kept in your account: one every four hours while you work, and one before any fresh start, restore or large deletion. The last 120 are held.

What is real in this file, and what is not yet

Rules that drive alerts and the brief

Turn them off or change the thresholds