Why a spreadsheet is a good place to start
Most collections begin as a list: a notebook, a note on a phone, the back of a receipt envelope. A spreadsheet is the next step up. It's free, it sorts and filters, it adds up values, and it opens on almost anything. More importantly, if you lay it out with consistent columns from the start, it moves cleanly into any other tool later, including an insurance schedule or an inventory app.
The template above is a plain CSV (comma-separated values) file. That's deliberate. CSV has no formulas, macros or formatting to break, every spreadsheet program can open it, and it's the format that import tools expect.
The columns, and what goes in each
| Column | What to enter | Example |
|---|---|---|
| Make | Manufacturer or importer, as marked on the gun | Ruger |
| Model | Model name or number as marked, plus variant | 10/22 Carbine |
| Serial Number | Exactly as stamped, letters and dashes included | EXAMPLE-0001 |
| Type | Handgun, Rifle, Shotgun or Other | Rifle |
| Caliber | Caliber or gauge | .22 LR |
| Barrel Length | Inches, number only | 18.5 |
| Purchase Date | YYYY-MM-DD | 2021-06-14 |
| Purchase Price | Number only, no $ sign or commas | 289.99 |
| Purchased From | Dealer, private party or "Inherited" | Local dealer |
| Condition | A consistent grade: New, Excellent, Very Good, Good, Fair, Poor | Excellent |
| Estimated Value | Today's value, number only | 325 |
| Notes | Optics, upgrades, where the receipt is, anything else | Receipt in safe binder |
The two example rows in the file use made-up serial numbers. Delete them before you add your own.
Five habits that keep a spreadsheet useful
1. Format the serial number column as text
This is the most common way spreadsheets quietly damage an inventory. Spreadsheet programs try to be helpful with anything that looks like a number: a serial like 0012345 loses its leading zeros, a long numeric serial can turn into scientific notation like 1.23E+11, and something like 3-14 can become a date. Before you type or paste serials, select the column and set its format to Text (Format → Number → Plain text in Google Sheets; Format Cells → Text in Excel). If you open the CSV by double-clicking it, Excel applies its own guesses on the way in, so check the serials after opening, or use Excel's Data → From Text/CSV import and set that column to Text.
2. Keep one item per row and one kind of thing per column
Don't merge cells, don't put two guns on one row, and don't mix units in a column ("18.5" in one row, "18 1/2 in" in the next). Sorting, totals and imports all depend on every row having the same shape. If you want to record optics or accessories, either use the Notes column or keep a second sheet for them with its own columns.
3. Use plain numbers for money and lengths
Enter 1249.00, not $1,249. You can format the column to display a currency symbol, but the value underneath should be a plain number, so SUM works and imports don't misread the comma as a column break.
4. Write dates as YYYY-MM-DD
2021-06-14 means the same thing everywhere. 06/07/21 means June 7 in the US and 6 July in most other places, and some programs will silently pick the wrong one.
5. Keep the spreadsheet with your photos, and keep a copy offsite
A spreadsheet holds the facts; photos and receipts back them up. A simple convention helps: name photo files with the serial number (EXAMPLE-0001-left.jpg, EXAMPLE-0001-serial.jpg) so you can always match them up. Then keep a copy of the whole folder somewhere other than the house. If you're doing this for insurance, our guide to inventorying firearms for insurance covers what photos and paperwork to collect.
A note on privacy
An inventory with serial numbers, values and where things are kept is sensitive. Treat the file like any other sensitive document: don't email it around unencrypted, don't leave it in a shared folder, and think about who can get to the computer or cloud account it's stored in. Excel and Numbers can password-protect a file; in Google Sheets, check the sharing settings and the security of the Google account itself. A CSV can't be protected on its own, so keep your working copy in your spreadsheet program's own format and use the CSV only for importing.
Already have a list in another layout?
You don't have to start over. Rename your existing column headers to match the ones above, or just add the missing ones; a column you don't have can stay empty. If you've been filling in ATF's Personal Firearms Record, its columns map onto these almost one to one. See the ATF Personal Firearms Record and how to keep one digitally.
When a spreadsheet stops being enough
Spreadsheets are great at lists and poor at everything around them. Photos live in a separate folder, receipts in a drawer, round counts and cleaning dates in your head, and the file on your laptop isn't with you at the gun counter or the range. That's usually the point where people move to an app.
This template uses the same column names as GunCollector's spreadsheet import, so a file built from it imports directly: each row becomes a firearm record, and you can then add photos, receipts and serial-number scans to each one. GunCollector also handles ammo, NFA items, range trips and maintenance, and builds a valuation and insurance report from the whole collection. The free plan covers up to five firearms, and you can export everything back out at any time.