About ThenPrice & methodology
Effective Date: August 2026
ThenPrice answers one question — what did it cost? — from the public record. It covers the United States (from 1913) and the United Kingdom (from 1800), item by item and year by year. ThenPrice is operated by Cien Rios LLC, Miramar, Florida. Contact: support@cienrios.com.
Where the numbers come from
Every US figure is drawn from the U.S. Bureau of Labor Statistics via FRED (public domain). Every UK figure is drawn from the Office for National Statistics, used under the Open Government Licence v3.0. Series identifiers are shown on each page's provenance panel, so any figure can be traced back to the exact government series it came from. We read the source page for every series before publishing it — names and units are never inferred from a series ID, and discontinued series are either excluded or explicitly labeled.
Verified vs. estimated — the core distinction
A price badged Verified is an observation: the statistical agency recorded that price in that year. A price badged Estimated is a back-cast: the earliest observed price projected backwards along the headline inflation index (CPI for the US, the ONS long-run RPI composite for the UK). The two are never mixed silently — every figure on the site carries its badge, and estimates state what they were projected from.
Back-casts degrade with distance. Beyond roughly 40 years, relative prices have moved enough that a CPI back-cast can be badly wrong — groceries in particular were far more expensive relative to other goods before modern agriculture — so deep estimates carry an explicit warning, not just a quieter badge.
What we refuse to guess
- Wages are never estimated.Back-casting earnings along inflation would erase real wage growth and invent figures the record does not support. Years before a wage series begins say "no record" instead of showing a guess.
- Dead series are not passed off as current.Where an agency discontinued a series (the ONS ended its average-price series in 2025), the "price today" is labeled as an estimate projected from the last observation — never presented as a live figure.
- Measurement changes are disclosed. When an agency changed what a series measures mid-history, the affected pages say so on the page.
Working-time figures
Pages that show a price "in working time" divide the observed price by a wage observed in the same year: the federal minimum wage for the US (hourly), and average weekly earnings for the UK. UK figures are expressed as what a week's pay bought rather than in hours, because converting a week to hours would smuggle in an hours-per-week assumption the record does not contain. If either side of the division is not an observation, the figure is simply absent.
The inflation calculator
The inflation calculator (and its UK counterpart) converts amounts between years using annual averages of the same headline indexes that power the estimates. It measures general purchasing power; individual items drift from the average, which is exactly what the rest of the site documents.
Reuse, citation, and data
Charts can be embedded and figures cited freely with a link back to the source page; every result page offers copy-ready snippets. Each item's full annual series can be downloaded as CSV from its history page. The underlying data is public — BLS/FRED material is public domain, ONS material is OGL v3.0 and requires attribution to ONS, which our pages and embeds carry.
Corrections
If a figure looks wrong, it is either our error or the record's — both are worth knowing. Write to support@cienrios.com with the page URL; corrections ship as data fixes, not silent edits, and the provenance panel will reflect the corrected series.