Methodology
How we pick
Every score on this site is computed from manufacturer-published specifications by the formula below. You can recompute any of them by hand, and we would rather you did.
How a pick is chosen
The five steps
- 01Start from the job's air demand, not the product range. We look up what the tool consumes at 90 PSI, and whether it consumes it in bursts, intermittently, or continuously. Duty class matters more than the CFM figure, because a burst tool draws from tank storage and a continuous tool draws from pump output.
- 02Read the manufacturer's specification sheet for every candidate. CFM at 90 PSI, CFM at 40 PSI, tank volume, maximum pressure, duty cycle, noise, weight, pump type. Where a manufacturer does not publish a figure, we record that it is not published rather than sourcing it from a retail listing or estimating it.
- 03Apply a documented sizing margin. Required CFM = highest published tool demand at 90 PSI x 1.25. The 25% covers three real losses published specs exclude: pressure drop through hose and fittings, a pump delivering less than rated once hot, and the slightly thirstier tool you will buy next.
- 04Rank by the cheapest unit that genuinely clears the bar - not by price alone, not by capability alone, and never by commission. The top pick on a page is frequently not the most capable machine on it.
- 05Name what each pick cannot do. Every product card on this site has a limits section, and it is not a formality: a 2.6 CFM pancake breaks lug nuts and cannot run a die grinder, and saying so is more useful than a fifth positive bullet.
Recompute it yourself
The scoring formula, in full
Scores are out of 10 and are a weighted average of sub-metrics, each of which is normalized linearly between a floor and a ceiling drawn from the range that actually exists in our roster. Every product card has an expandable panel showing each sub-metric's score, weight and basis, so no score is a black box.
For compressors, the weights are: air flow at 90 PSI 40%, stored air 25%, noise 15%, portability 10%, and specification transparency 10%.
| Metric | Weight | Scale | Rationale |
|---|---|---|---|
| Air flow | 40% | 0.7 to 6 CFM at 90 PSI | The number that decides which tools run at all. 6 CFM is the top of what a 120V garage compressor realistically delivers; 0.7 is a 1-gallon trim unit |
| Stored air | 25% | 125 to 3,500 (gallons x max PSI) | Decides how long you can draw more than the pump makes. Pressure matters as much as volume, which is why this is two numbers rather than gallons |
| Noise | 15% | 58 to 85 dBA, inverted | 58 dBA is the quietest figure published in our roster. Past about 85 a compressor is genuinely unpleasant. Not published scores a neutral 5 |
| Portability | 10% | 20 to 90 lb, inverted | A compressor you have to move before using is a compressor you use less. Not published scores a neutral 5 |
| Spec transparency | 10% | 0 to 6 figures published | CFM at 90, CFM at 40, dBA, duty cycle, recovery time, weight. A brand that publishes these measured them |
Important
What the score is not
It is not a test result. Nothing on this site has been bench-tested, and the score contains no measurement we made. It is a transparent weighting of figures the manufacturer published.
It is not a durability prediction. We have no long-term reliability data, no failure statistics, and no teardowns. A product could score 8.5 here and have a mediocre pump, because we are scoring documented specification quality rather than build quality.
It is never structured data. The visible score is ordinary page content and it deliberately never appears in JSON-LD. Google's structured-data policies treat Review and aggregateRating markup as a first-party review rating of a product, which this is not - marking it up that way would contradict our own copy and put the site at risk.
Sources
Where our numbers come from
Tool air demand comes from two published references, both linked on every page that uses them. Ingersoll Rand's air consumption chart for automotive service shops, which carries its own caveat that the figures are averages and should not be considered accurate for any particular make of tool. And Engineering ToolBox's air tool consumption table, which states its own basis: the ratings assume a 25% load factor, and full performance requires four times the volume.
Where those two references publish different figures for the same tool class, we show both rather than averaging them into a number neither published. That is why our CFM chart has rows reading 3 to 5 CFM rather than 4.
Product specifications come from the manufacturer's own product page, dated to September 2026 and linked on the product card. Where a specific figure comes from a distributor listing rather than the brand's own page - which happens when a manufacturer's site is unreachable - the source label says so.
The Compressed Air and Gas Institute is the standards body behind the terminology we use, and its handbook is the reference for the formal definitions of CFM, SCFM and duty cycle rather than our summaries of them.
The honest list
What we do not do
- We do not bench-test. No product on this site has been used by us, and no page implies otherwise. Phrases like 'in our testing' or 'after 40 hours of use' appear nowhere because none of it happened.
- We do not accept payment for placement or ranking. Commission rates do not enter the ranking logic, which is why several pages recommend an electric tool or a cheaper unit we earn less on.
- We do not publish prices we cannot verify. There is no live price feed on this site, so every buy control reads 'Check price on Amazon' rather than showing a number that might be months old.
- We do not publish ratings or review counts. We have no first-party rating data and we will not republish scraped ones.
- We do not estimate a missing specification. Not published means not published, and it is recorded rather than filled in.
- We do not give electrical installation guidance. Adding a circuit is licensed work under the National Electrical Code and we are not qualified to advise on it.
Keeping it current
Review cadence
Roundups and job pages are reviewed quarterly, because model availability shifts fastest and we have no automated availability feed. Reference charts and comparisons every six months. Guides annually. The calculator's formula annually.
A quarterly roundup review checks four things: is every pick still sold, does every outbound link still resolve, do the specs still match the manufacturer's current sheet, and has a new model appeared that beats a pick on value.
The modified date on a page changes only when the content substantively changes. A date that moves without the content moving is a freshness signal fabricated for a crawler, and we would rather show an honest older date than a dishonest recent one.
Corrections
How to tell us we are wrong
Email contact@psiandhose.com with the page and the figure. Specification corrections are the most likely and the easiest to act on - manufacturers revise spec sheets, and if our number no longer matches theirs, theirs wins.
This matters more on this site than on most, because the whole editorial position rests on the numbers being checkable. A site that shows its arithmetic and gets the arithmetic wrong has nothing left.
Sources
Where these numbers come from
- Compressed Air & Gas Institute - Compressed Air & Gas Handbook
The industry standards body for compressed air terminology and system design.
- Ingersoll Rand - Air Consumption Chart for Automotive Service Shops
Figures are for average service-shop usage. The chart carries its own caveat: "Always check with tool manufactures for actual air consumption of tools being used. The above is based on averages and should not be considered accurate for any particular make of tool."
- Engineering ToolBox - Air Tools, Air Consumption
Tool-class consumption at roughly 90 psi. The table states its own basis: "The ratings are based on 25% load factor - or tools running 25% of the time. Full performance requires 4 times the volume."
- NFPA 70 (National Electrical Code) - standard landing page
Accessed September 2026. If a figure on this page does not match the manufacturer's current sheet, tell us at contact@psiandhose.com and we will correct and date the change - see our editorial policy.