How the calculation works
Price per GB = price ÷ (capacity of one unit in GB × units in the pack); 1 TB = 1,000 GB
A worked example
A 256 GB card at $24.99 costs $0.098 per GB. A two-pack of 128 GB cards at $17.99 holds the same 256 GB for $0.070 per GB, and a 32 GB RAM kit (2 × 16 GB) at $95.99 costs $3.00 per GB.
Count every gigabyte once
A RAM kit sold as "32GB (2x16GB)" holds 32 GB, not 64: enter 16 GB and 2 modules, or 32 GB and 1. A five-pack of 64 GB cards holds 320 GB. A USB stick with both a USB-A and a USB-C plug is one stick.
Why price per GB
Bigger cards and kits usually cost less per gigabyte, but not always, and pack sizes differ. Dividing by the capacity puts a 32 GB card, a 1 TB card and a five-pack on the same scale. Compare within one kind of memory only: a cheaper gigabyte of DDR4 is no use in a DDR5 board.
Common questions
Why does my 256 GB card show less space?
Labels count 1 GB as 1,000,000,000 bytes; Windows counts in binary units of 1,073,741,824 bytes and calls them GB. A 256 GB card shows as about 238 GiB before formatting. Every card loses the same share, so prices per GB still compare.
Does a faster card cost more per GB?
Often. V60 and V90 cards and fast CFexpress cards cost more per gigabyte than V30 cards of the same size. Buy the speed class your camera needs, then the cheapest gigabyte within it.
How do I count a RAM kit?
Enter the capacity of one module and the number of modules (16 GB × 2 for a 32 GB kit), or the kit's total with 1. Both give the same price per GB.
Method: arithmetic from the label values you enter. Reviewed .