Guide

The watch collection spreadsheet, and where it stops working

Nearly every collector starts with a spreadsheet. Here is a template worth starting from — and an honest account of the point at which it stops earning its keep.

Updated 6 August 2026 · 6 minute read

What to put in the columns

Most collection spreadsheets are built twice: once in a hurry, and again a year later when it turns out the first one was missing the columns that mattered. These are the fields worth having from the start.

Identity

• Brand and Model — separate columns, always. Combined into one, you can never group by brand later.
• Reference number — the single most useful field for insurance, resale and finding parts. Copy it from the caseback or the papers, not from memory.
• Serial number — keep it, but keep the sheet private.
• Year of manufacture — distinct from when you bought it.

Money

• Purchase date, purchase price and currency.
• Retail price at the time — this is the column people forget, and the one that tells you years later whether you bought well.
• Where bought — dealer, private sale, auction. It matters for provenance.

Physical

• Lug width — in millimetres. Without it you cannot answer "which of my straps fit this?", which is the question you will ask most often.
• Case diameter and lug-to-lug — the two numbers that actually predict whether a watch wears well on your wrist.
• Movement and power reserve.

Upkeep

• Last service date and service interval.
• Warranty expiry.
• Condition notes — the scratch that was already there when you bought it.

The second sheet nobody builds: straps

A collection of eight watches and fifteen straps is not twenty-three things. It is a hundred and twenty possible combinations, and you probably wear about nine of them. A strap sheet needs little more than maker, material, colour, width and what you paid — but width is what lets you cross-reference against lug width and see, for each watch, which straps you own that would actually fit it.

This is where a spreadsheet starts to creak. Cross-referencing two sheets to answer "what could I put on the Speedmaster tonight that I have not tried?" is a lookup formula most people write once and never maintain.

The third sheet, and the real problem: wear

The inventory sheet tells you what you own. It cannot tell you what you actually wear, and that turns out to be the more interesting question by a distance.

To answer it in a spreadsheet you need a row per day: date, watch, strap. That is 365 rows a year, entered by hand, from a laptop, on a day you probably were not thinking about spreadsheets. It is not the concept that fails — it is the friction. A wear log is only useful if it is complete, and completeness needs the entry to take three seconds on the device already in your hand.

A collection sheet you update four times a year works fine. A wear log you update four times a year is worthless.

That asymmetry is the whole argument. Inventory is a low-frequency, high-value record and a spreadsheet is genuinely good at it. Wear is a high-frequency, low-effort record, and spreadsheets are terrible at those — which is why nearly every collector who tries has a wear log that stops in about March.

If you stay with a spreadsheet

• Use one row per item and never merge cells. Merged cells break every sort you will ever want.
• Keep prices as plain numbers with a separate currency column, not as text like "£4,200".
• Put dates in ISO form — 2026-08-06 — so they sort correctly regardless of locale.
• Back it up somewhere that is not the same laptop. An insurance record that burned in the same fire as the watches is not an insurance record.