Enter your hydrogen mass requirement and constraints. The calculator returns the cylinder volume, mass, and system-level penalty for each pressure tier — and recommends the right one based on whether your application is mass-constrained, volume-constrained, or balanced. Driven by real H₂ density curves and Type IV PET cylinder mass scaling.
Reserve added on top of usable H₂ mass to size the cylinder.
Note: cylinder mass uses Type IV PET scaling calibrated to a 6.8 L cylinder at 1050 bar burst weighing 2.0 kg. System mass adds an estimated regulator and valve penalty that scales linearly with inlet pressure (≈40% heavier at 700 bar vs 300 bar). Reserve and safety factor apply to all tiers equally.
Required H₂ mass + reserve → required volume = mass / density(P, T). H₂ density at 25 °C is taken from a real-gas table (NIST-derived), accounting for Z > 1 above 200 bar.
Type IV PET cylinder mass scales linearly with burst-pressure × volume:
m_cyl = K_PET × volume × burst_pressure
K_PET = 0.000280 kg/(L·bar of burst), calibrated against the MEYER HDRX-068 reference (6.8 L at 1050 bar burst → 2.0 kg).
The regulator, service valve, fittings, and fill nozzle scale with inlet pressure. The model adds an indicative system-mass overhead per tier:
For larger systems (vehicle, launch), scale these proportionally.
Infrastructure availability acts as a hard filter — if you’ve selected “350 bar only,” 700 bar is excluded from recommendation regardless of mass / volume score.
For programme-specific cylinder design, send us your H₂ mass, mission profile, envelope constraints, and refuelling infrastructure — we’ll give you cylinder specs, regulator pairing, and ballpark cost in 3 working days.
