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Gas Blending

The Gas Blending calculator computes the exact fill sequence needed to mix a target gas from your current tank contents. It supports both nitrox and trimix blending using the partial pressure method.

Safety Notice

Gas blending requires specialized training and oxygen-clean equipment. Only blend gases if you are properly certified and equipped.

Premium Feature

The Gas Blending calculator requires an active premium subscription.

Nitrox blending​

Nitrox blending uses the partial pressure method to calculate how much pure oxygen to add before topping off with air.

Inputs:

  • Current tank pressure and current O2 percentage -- what is already in the tank
  • Target pressure and target O2 percentage -- what you want to end up with

Output -- step-by-step procedure:

  1. Add a specific amount of pure O2 (in bar or psi)
  2. Intermediate pressure after the O2 fill
  3. Top off with air to the target pressure
  4. Final mix composition
Nitrox blending calculatorNitrox blending calculator

Nitrox blending calculator showing current and target mix inputs -- calc-nitrox-blending-light.png / calc-nitrox-blending-dark.png

Trimix blending​

Trimix blending extends the process to three components: oxygen, helium, and nitrogen (which is supplied through the air top-off). The nitrogen fraction is calculated automatically as 100% minus O2% minus He%.

Inputs:

  • Current tank pressure, current O2 percentage, and current He percentage
  • Target pressure, target O2 percentage, and target He percentage

Output -- step-by-step procedure:

  1. Add a specific amount of pure O2 (in bar or psi)
  2. Add a specific amount of pure He (in bar or psi)
  3. Top off with air to the target pressure
  4. Final mix composition
Trimix blending calculatorTrimix blending calculator

Trimix blending calculator showing O2 and He inputs for both current and target mixes -- calc-trimix-blending-light.png / calc-trimix-blending-dark.png

Reading the results​

The results section breaks down each blending step with the exact pressures to add. This gives you a clear, actionable procedure to follow at the fill station.

Step-by-step blending resultStep-by-step blending result

Step-by-step blending result showing the fill sequence with intermediate pressures -- calc-blending-steps-light.png / calc-blending-steps-dark.png