Price Index Methodology & How to Cite
RAMList publishes two daily, citable price indexes — one for computer memory and one for solid-state storage. Both are built the same way: take the median price of new, validated products across a fixed set of representative segments, rebase each segment to 100 on a baseline date, and combine them with fixed weights so the index measures price change, not which products we happen to be tracking. Once a day is recorded it is frozen, so the published series and downloads never shift under you.
RAM Price Index
- Baseline: June 1, 2026 = 100
- Methodology version: 1.0
- Latest value: 141.3 (as of Sep 19, 2026)
- Coverage: DDR5 & DDR4, by capacity and speed
SSD Price Index
- Baseline: September 1, 2026 = 100
- Methodology version: 2.1
- Latest value: 93.6 (as of Sep 19, 2026)
- Coverage: NVMe & SATA, measured in $/TB
How both indexes are calculated
Median, not average. For each segment we take the median (middle) price of new, validated products, so a handful of unusually cheap or expensive listings can't skew a segment.
Rebased to 100. Each segment's median is divided by its own baseline value and multiplied by 100, so every segment starts at 100 on the baseline date and the index tracks percentage change.
Fixed weights. The headline index combines the segment indices using fixed weights across representative segments — not listing counts — so a change in how many of each we track can't move the index on its own. When a segment has no data on a given day, its weight is redistributed across the segments present.
What's excluded. Used stock and records that fail our normalization checks are excluded. For SSDs, external/portable drives, multi-capacity lots, and spinning hard drives are never counted — it is a solid-state index measured in dollars per terabyte.
SSD index segment weights
The SSD Price Index (version 2.1) combines these segments with fixed weights:
- 1TB PCIe 4.0 NVMe — 20%
- 2TB PCIe 4.0 NVMe — 25%
- 4TB PCIe 4.0 NVMe — 15%
- 1TB PCIe 5.0 NVMe — 10%
- 2TB PCIe 5.0 NVMe — 10%
- 1TB SATA — 10%
- 2TB SATA — 10%
Data sources & freshness
Today's figures come from live listings across the retailers we track — Newegg, eBay, Walmart and Best Buy — refreshed throughout the day. Amazon prices are shown on product pages but are not retained in the historical index (their API terms only permit displaying a price fetched in the last 24 hours). Days before daily recording began are reconstructed once from our price history and then frozen.
Using & citing the data
The RAMList price indexes are free to use in articles, research, videos and other publications, including the full daily series available as CSV and JSON above. We just ask for a link back so readers can find the live data.
Suggested citation:
Source: RAMList RAM & SSD Price Index — ramlist.com/price-indexes.
Questions about the methodology or a specific segment? Get in touch.