Hydrogen Storage Tank Sizing Calculator
Hydrogen’s low density at normal pressure means storing meaningful quantities is fundamentally a space problem — and the solution is either very high pressure or cryogenic liquefaction. This calculator takes the mass of hydrogen you need to store and a storage density (auto-filled by your storage method), then reports the required tank volume in cubic meters and gallons. For the energy it costs to reach those high pressures in the first place, see our Hydrogen Compression Energy Calculator, and for how much renewable electricity it takes to produce the hydrogen you are storing, see our Green Hydrogen Production Calculator.
Total kilograms of hydrogen you need to store in the tank.
Selecting a method auto-fills the storage density below (still editable). 700 bar is standard for fuel cell vehicle tanks; liquid hydrogen is used where minimum volume matters most.
Hydrogen mass per unit tank volume at the chosen pressure or phase. Values sourced from DOE hydrogen storage technology assessments.
required hydrogen storage mass ÷ storage density
required tank volume (m³) × 264.172
Results update live as you type. For planning and field-check estimates — always verify against applicable standards and equipment ratings.
How we calculate this →Storage pressure and phase change the space equation dramatically: the same 500 kg of hydrogen needs about 21.3 m³ as compressed gas at 350 bar, but just 7.1 m³ as cryogenic liquid at -253°C -- roughly a third of the volume. That's exactly why aircraft and rockets favor liquid hydrogen despite the added complexity of cryogenic storage: every cubic meter saved is space that can go toward passengers, cargo, or payload instead of fuel tanks.
How hydrogen storage tank sizing is calculated
This calculator ties the physical tank volume required to store hydrogen to two inputs: how much hydrogen you need to store, and how densely that hydrogen can be packed into a given volume at the chosen pressure or phase. Two quantities tie the calculation together.
Required Tank Volume (m³) = Required Hydrogen Storage Mass (kg) ÷ Storage Density (kg/m³). Storage density is the mass of hydrogen that fits in one cubic meter of tank volume at a given pressure and temperature; at 500 kg and 23.5 kg/m³ (the 350 bar compressed gas value), that is 500 ÷ 23.5 = 21.28 m³. The same 500 kg needs 34.5 m³ at 200 bar (14.5 kg/m³), 12.5 m³ at 700 bar (40.0 kg/m³), and only 7.1 m³ as cryogenic liquid at -253°C (70.8 kg/m³) — roughly a third of the 350 bar volume.
Required Tank Volume (gallons) = Required Tank Volume (m³) × 264.172, since one cubic meter equals 264.172 U.S. gallons; at 21.28 m³, that is 21.28 × 264.172 = 5,621 gallons. The conversion is exact; only the storage density varies with the chosen method.
Hydrogen has very low density at normal atmospheric pressure (about 0.09 kg/m³), so storing meaningful quantities requires either extremely high pressure (compressing the gas into a smaller space) or cryogenic liquefaction (cooling it to -253°C so it condenses into a liquid). Liquid hydrogen’s density of 70.8 kg/m³ is roughly 3x that of 350 bar compressed gas, which is why aerospace applications favor liquid storage despite the added complexity of insulated cryogenic tanks and inevitable boil-off losses. Compressed gas storage is simpler, cheaper, and more practical for many stationary and shorter-duration applications despite its larger footprint. Data sources: Hydrogen storage density values from DOE hydrogen storage technology assessments; compressed gas storage specifications from tank manufacturers; cryogenic liquid hydrogen properties from NIST and aerospace engineering references; fuel cell vehicle tank pressure standards (SAE J2601).