ModelCalcs.uk
Airbrush Pressure Calculator â Optimal PSI Settings
Find the recommended airbrush pressure based on your nozzle size, paint type and technique.
Pressure also shown in bar (1 psi = 0.0689 bar). Always thin your paint to suit and test on scrap before painting the model.
How We Calculate This
This calculator uses recommended pressure ranges based on nozzle diameter, paint viscosity and spraying technique. Smaller nozzles need less pressure; thicker paints and larger coverage areas need more.
Frequently Asked Questions
For most acrylic paints through a 0.3mm nozzle, start at 15 PSI for general work. Reduce to 10-12 PSI for fine lines and increase to 18-22 PSI for base coating larger areas. Always test on scrap first.
Primer and surfacer paints are thicker and contain more solids than colour coats, so they need more pressure to atomise properly and lay down an even coat without texture. Aim for 20-30 PSI for most well-thinned primers; thicker surfacers sprayed through a larger 0.5mm nozzle can run up to 35 PSI. Thinning the primer first lets you keep the pressure lower.
Too-low pressure causes spattering, uneven coverage and a rough texture. The paint is not atomised into fine enough particles. Increase pressure gradually until you get a smooth, even spray pattern.
Related Calculators
Thinning Ratio Calculator
Calculate the correct paint-to-thinner ratio for brush, airbrush or spray can.
Dry Brush Calculator
Work out paint quantity and recommended brush sizes for dry brushing techniques.
Paint Brand Mixing Calculator
Find equivalent paint colours across Citadel, Vallejo, Tamiya, AK and Mr. Color brands.
Paint Mix Calculator
Mix two or more paint colours by ratio to get the exact shade you need.
Spray Coverage Calculator
Estimate how much spray paint or primer you need for your model surface area.
Was this calculator helpful?
Last updated: February 2026
All calculations are estimates. Always verify quantities before purchasing materials.