Can this calculator tell me what size compressor I need?

No — not from three broad choices. Required capacity depends on the working pressure and airflow your exact airbrush and paint need, plus the duty cycle your sessions demand. Those figures are published by the airbrush maker, paint maker and compressor maker, so the tool returns a specification checklist instead of an invented horsepower, tank or pressure number.

What specifications should I collect before buying?

Collect the airbrush's working pressure range, the paint maker's thinner and pressure guidance for that exact line, the airflow requirement at your working pressure, a candidate's continuous delivery and duty cycle, its regulator and moisture-control setup, hose and fitting compatibility, and its noise figure with the measurement conditions. If any of these is missing, the required capacity is undetermined.

What does horsepower tell me about a compressor?

Horsepower is a motor rating. It does not convert into a working pressure, airflow, duty cycle or tank size, and two units with the same horsepower can behave differently. Use horsepower only as one line on the spec sheet, and compare the figures the maker publishes at your actual working pressure.

Do I need a tank on an airbrush compressor?

Not necessarily. A tank can smooth piston pulses and give the motor time to rest, but a tankless unit can suit short detail sessions if it holds the working pressure your airbrush needs. Compare continuous delivery, duty cycle, regulator range and noise for the sessions you actually run rather than treating a tank size as a requirement.

Which airflow figure should I compare?

Compare airflow figures quoted at the same working pressure and in the same unit — for example L/min at 20 psi against L/min at 20 psi. Do not compare a figure quoted at maximum pressure with one quoted at your spraying pressure, and do not estimate a missing figure from horsepower or tank size. Ask the maker for the figure at your working pressure.

Is a twin-piston compressor better than a single-piston one?

Not categorically. Piston count alone does not establish continuous delivery, duty cycle, cooling or noise. A single-piston unit can suit fine detail work, while a twin-piston unit may help with sustained output — but only the candidate's published figures at your working pressure show whether either meets the job.

Compressor buying tool

Airbrush Compressor Size Calculator

Tell the checklist what you build, what you spray with and how long you spray, and it returns the published specifications still to obtain: the working pressure and airflow your airbrush and paint need, a candidate's continuous delivery and duty cycle, the regulated air supply, hoses and fittings, and noise. It cannot determine required capacity from those three choices alone — so it does not invent a horsepower, tank or PSI result.

Your setup

Three answers set the context for a specification checklist. Everything is worked out in your browser, so nothing you choose here is uploaded or stored.

What do you mostly build?

Pick the closest match. Scale changes the workload, not a required compressor rating.

What airbrush are you using?

Needle size and feed type narrow the context; your airbrush manual gives the working pressure.

How much do you spray at once?

Longer sessions put more demand on continuous delivery, duty cycle and cooling.

Your specification checklist

Choose your subjects, your airbrush setup and how much you spray, then select Build my checklist. You get the published specifications still to obtain — working pressure, airflow, duty cycle, air supply, fittings and noise — with concrete next checks. No horsepower, tank or pressure result is invented from these choices.

How this checklist works

The tool does not calculate a compressor size. Horsepower, tank size and piston count do not determine the pressure or airflow a particular airbrush and paint need, and the three choices do not contain those figures. What the tool does instead is turn your context into the list of published specifications you still have to collect.

Start with the working pressure. Your airbrush maker's manual and the paint maker's guidance for that exact line set the working range. Note whether a number is working pressure at the brush, maximum output pressure or a pressure-switch setting.
Find the airflow at that pressure. Look for L/min or CFM quoted at your working pressure. A figure quoted at maximum pressure is not interchangeable with one quoted where you spray.
Match a candidate's continuous delivery. Collect the airflow it can sustain, its duty cycle and its cooling method. Compare only figures quoted on the same basis.
Check the air supply and connections. A regulator that covers your working range, moisture control, and a hose and fittings that match your airbrush are part of the decision, not accessories.
Then judge noise for your room. Noise is a buying constraint that horsepower and tank size do not predict.

If a figure is missing, the required capacity stays undetermined. The checklist tells you what to ask for; it does not fill the gap with an estimate.

What the specifications mean

Working pressure (psi): The pressure at the airbrush while you spray, set with the regulator. This is the figure your airbrush and paint guidance should state.
Maximum output pressure (psi): The highest pressure the compressor can produce. It is not the pressure you spray at, and it does not tell you the airflow available at your working pressure.
Pressure-switch setting (psi): The on/off points at which the motor restarts and stops. A 40 psi on / 60 psi off switch describes tank control, not a recommended pressure at the brush.
Airflow (L/min or CFM): The volume of air delivered. Compare figures only at the same working pressure and in the same unit; a flow figure at maximum pressure does not describe flow at your spraying pressure.
Duty cycle and cooling: How long the unit can run relative to its rest period, and how it sheds heat. These decide whether a unit suits long sessions, and they are not predicted by horsepower.
Tank (litres): Stored air. A tank can smooth piston pulses and let the motor rest; it does not raise the working pressure, and a tank size alone does not establish continuous delivery.
Horsepower (hp): A motor rating. It does not convert into working pressure, airflow, duty cycle or tank size, so the tool does not use it to derive any of those.

Spec-reading examples

These are published maker figures, shown to demonstrate how to read a spec sheet. They are examples, not recommendations, and the tool does not convert horsepower into pressure or airflow.

Iwata Power Jet Pro (North American IS975): The maker lists a 1/6 HP motor, a 2 L tank, 1–50 psi working pressure, 75 psi maximum pressure, a 62 dB rating and 110–120 V 60 Hz. The working range and the maximum are different figures: 75 psi is not the pressure you set at the brush. The 62 dB figure is the maker's own rating and is not comparable with another maker's unmatched noise test.Iwata Power Jet Pro specification
Sparmax TC-620X: The maker lists an oil-less twin-cylinder piston, a 2.5 L tank, a pressure switch of 40 psi on / 60 psi off, airflow of 23–32 LPM and a mass of 10.4 kg. The switch values are tank-control settings, not the recommended pressure at the brush. Treat the airflow range as a delivery figure to compare only at the conditions the maker states.Sparmax TC-620X specification

For paint-side context, Iwata recommends Medea products for water-soluble paints and directs buyers to the paint label or manufacturer for other materials. That is a maker recommendation for a product family, not a universal thinner rule for every acrylic.

What this checklist does not do

It does not calculate horsepower, tank size, piston count, working pressure or airflow from your three choices. Those figures are not contained in the answers, and horsepower cannot be converted into them.
It does not know your airbrush's working pressure range or your paint line's thinner guidance. You supply those from the makers' documents.
It does not measure noise, duty cycle, refill time or moisture control, and it does not compare unmatched test figures as if they were equal.
It cannot tell you a specific model's real delivery at your working pressure. That comes from the manufacturer's spec sheet, manual or a direct question to the maker.
It will not tell you which brand to buy. It tells you which evidence to collect so a spec sheet means something when you read it.

Compressor sizing questions

Can this calculator tell me what size compressor I need?: No — not from three broad choices. Required capacity depends on the working pressure and airflow your exact airbrush and paint need, plus the duty cycle your sessions demand. Those figures are published by the airbrush maker, paint maker and compressor maker, so the tool returns a specification checklist instead of an invented horsepower, tank or pressure number.
What specifications should I collect before buying?: Collect the airbrush's working pressure range, the paint maker's thinner and pressure guidance for that exact line, the airflow requirement at your working pressure, a candidate's continuous delivery and duty cycle, its regulator and moisture-control setup, hose and fitting compatibility, and its noise figure with the measurement conditions. If any of these is missing, the required capacity is undetermined.
What does horsepower tell me about a compressor?: Horsepower is a motor rating. It does not convert into a working pressure, airflow, duty cycle or tank size, and two units with the same horsepower can behave differently. Use horsepower only as one line on the spec sheet, and compare the figures the maker publishes at your actual working pressure.
Do I need a tank on an airbrush compressor?: Not necessarily. A tank can smooth piston pulses and give the motor time to rest, but a tankless unit can suit short detail sessions if it holds the working pressure your airbrush needs. Compare continuous delivery, duty cycle, regulator range and noise for the sessions you actually run rather than treating a tank size as a requirement.
Which airflow figure should I compare?: Compare airflow figures quoted at the same working pressure and in the same unit — for example L/min at 20 psi against L/min at 20 psi. Do not compare a figure quoted at maximum pressure with one quoted at your spraying pressure, and do not estimate a missing figure from horsepower or tank size. Ask the maker for the figure at your working pressure.
Is a twin-piston compressor better than a single-piston one?: Not categorically. Piston count alone does not establish continuous delivery, duty cycle, cooling or noise. A single-piston unit can suit fine detail work, while a twin-piston unit may help with sustained output — but only the candidate's published figures at your working pressure show whether either meets the job.

Next steps

Once the specification list is complete, the airbrush itself is the other half of the setup. The same logic applies: match the tool to the job before you compare brands.