PC Airflow Simulator
Set up the fans in a 3D computer case, then watch how air moves past your graphics card and CPU cooler before you move any hardware.
Test Your Own Fan Layout for Free
Add, move, and speed up fans in a small Mini-ITX case, then press Run airflow. Items marked Pro come with a subscription.
Interactive airflow model
Load the model to see air move through the case in 3D.
- Real spinning blades Each fan is simulated as spinning blades that push on the air. They are tuned so one fan alone matches its maker's data, such as ARCTIC's P12 fan curve.
- Parts that slow the air Heatsink fins, radiators, dust filters, and the case's steel mesh all resist the air. So a fan moves less in a case than its box says, as the Noctua airflow guide explains.
- Air solved in 3D Standard detail splits the case and the air around it into about 170,000 cells, each 1 cm wide. The flow is worked out in every cell, even in the gaps between parts.
- Honest results Results are averaged once the air settles. Each run also shows how steady its averages are, so you can tell a real gain from noise.
See What Pro Adds
The free version uses the Mini-ITX case. PC Airflow Simulator Pro opens every case, including the common ATX mid-tower, plus every part and detail level. Planning one build? US$5 gets you a whole month of the full simulator. Computer Info Bits Pro adds the rest of our premium tools.
PC Airflow Simulator Pro
The full 3D simulator, and nothing else.
$5 per month
Billed every month. Cancel anytime.
$35 per year
Billed once a year. The same as 7 months.
Computer Info Bits Pro
Every Pro feature, on our site and in our Windows apps.
$10 per month
Billed every month. Cancel anytime.
$70 per year
Billed once a year. The same as 7 months.
Prices are in US dollars, plus sales tax where it applies. Cancel anytime. You keep access until the end of the period you've paid for. Payments are not refunded for unused time. Your receipt and license key arrive by email.
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Open your Pro dashboardEverything the full simulator includes
Every ready-made layout in every case, from a small Mini-ITX case to a full tower with 140 mm fans, including real Corsair, NZXT and Lian Li models.
Swap in different graphics card sizes, CPU coolers, or an AIO radiator. Runs can use 10 mm or 6.7 mm cells, sharper than the free version's 20 mm.
Save your builds and compare two layouts side by side with the same settings. Both plans include all of it. Computer Info Bits Pro also covers printable reports from our calculators, PC Reporter Pro, and the other premium tools as we add them. See what else Pro includes.
Planning a build? The full simulator is US$5 for a whole month.
See plansWhat you can learn before moving a fan
See the path: Watch air leave each fan with a swirl, flow around the parts inside, and exit the case.
Compare layouts: Save a build, change a fan, then run both layouts with the same settings.
Use the right level: Treat the result as a simulated estimate of air movement. It does not predict component temperatures.
Only need to compare intake and exhaust totals? Use the fan airflow calculator instead.
Build a Layout and Render the Airflow
The free version runs your layouts with 20 mm cells, in the Mini-ITX case only. Pro adds every other case type and finer 10 mm or 6.7 mm cells.
- Pick a fan layout, or keep the default one.
- Select a fan to change its position, direction, model, and speed.
- Select Run airflow and wait for the result.
- With Pro, save the build before you change a fan to compare the two layouts.
The simulation runs on your computer. Browsers that support WebGPU use the graphics card and finish much faster.
Read the Airflow View
- Moving streaks
- Each streak points the way the air moves. Deep blue is slow air and pale cyan is fast air, not colder air.
- Fan rings and arrows
- Blue marks an intake fan and orange marks an exhaust fan.
- Air-speed slice
- Turn on the slice to see air speed across one flat cut through the case. Move it to check any depth.
- Fan results
- Each fan shows its airflow in CFM and the pressure its blades create. Compare these numbers between layouts.
- Case pressure
- Shows if your case runs positive or negative. Positive means more air comes in than goes out, so the extra leaves through gaps and helps keep dust out.
- Graphics card and cooler air
- Shows how much air the graphics card fans and CPU cooler fan pull in with your layout. An AIO radiator shows how it changes the airflow through your case.
Use the Result as a Comparison
A real case has cables, small gaps, and grilles that the model simplifies. The graphics card and CPU cooler are simplified in the calculation, and their fans run at typical speeds you cannot change yet. Numbers can also shift a little between the calculation detail settings, so compare layouts at the same setting.
Make one change at a time, then test the real computer under the same load and room conditions. The PC airflow optimization guide explains fan direction, common layouts, and repeatable testing. To see how one fan's direction changes a result, read our rear top fan test.