What is the 3-2-1 backup rule?

The 3-2-1 rule means keeping 3 copies of your data, on 2 different types of media, with 1 copy offsite. For photographers this typically means the working drive, a local backup drive, and a cloud backup service.

What average file size should I use?

RAW files from modern cameras are typically 25-60MB. JPEGs are 5-15MB. If you shoot RAW+JPEG, use a combined average. A full-frame 45MP camera produces ~50MB RAW files, while a 24MP APS-C camera produces ~25MB RAW files.

How much does cloud storage cost?

Cloud storage for photographers typically costs £5-10 per month per TB. Services like Backblaze B2 are cheaper (~£5/TB/month) while Google One and iCloud are around £8-10/TB/month. The default uses £80/TB/year.

How long do external drives last?

External hard drives typically last 3-5 years with regular use. SSDs last longer (5-10 years) but cost more. Budget for drive replacement every 3-5 years, and always keep multiple copies to protect against drive failure.

PhotoCalcs

Image Backup Calculator — Storage Planning

Calculate total storage needed for your photo archive, external drive sizing, and compare cloud vs local backup costs using the 3-2-1 rule.

Images Per Year

Enter the images per year

Average File Size

RAW ~25-50MB, JPEG ~5-15MB

Years to Store

Enter the years to store

Backup Copies

3-2-1 rule recommends 3 copies

How We Calculate This

This calculator estimates total archive size over time, then calculates storage needs with multiple backup copies following the 3-2-1 rule.

The formula

Total storage = Images/year x File size x Years

With backups = Total storage x Backup copies

Frequently Asked Questions

Last updated: March 2026

All calculations are estimates based on standard optical and photographic formulas. Results may vary with specific equipment.