Hydrogen tools & calculators

Convert key hydrogen properties instantly and explore how purity links to dew point and moisture.

Make quick, defensible conversions

Use the calculators below to translate between normal volumetric flow, mass flow, gravimetric energy content and dew point equivalents for hydrogen streams. Results assume normal conditions (0 °C, 1.013 bar) unless noted.

Flow and energy conversions

Switch between Nm³/h, kg/h and energy intensities using an industry standard density of 0.08988 kg per Nm³.

Hydrogen flow converter

Enter either normal volumetric flow or mass flow. The counterpart is calculated automatically.

Nm³/h
kg/h

Assumes dry hydrogen at 0 °C and 1.013 bar (0.08988 kg/Nm³).

Gravimetric & volumetric energy

Convert electrolyser or fuel cell figures between kWh per kg and kWh per Nm³.

kWh/kg
kWh/Nm³

Uses the same density assumption as the flow converter.

Hydrogen purity to dew point

Estimate moisture content and dew points from a purity specification. Enter the dry gas purity and line pressure to see the equivalent dew point and ppm values.

Moisture is assumed to be water vapour. Dew point uses an Arden Buck correlation.

Gas data

Gas type
Hydrogen
Molecular weight
2.016 g/mol
Line pressure
30 bar
Parts per million
10 ppm(v)
Parts per million by mass
89 ppm(w)

Dew point & absolute moisture

Dew point (observed)
-80 °C
Dew point @ 1.013 bar
-96 °C
Absolute humidity
0.000 g/m³ @ 15 °C
Moisture loading
0.00 lb/MMSCF

Outputs are rounded. For very dry gas (<1 ppm) dew point is reported as below the calculation range and lb/MMSCF uses the same standard reference conditions.

Hydrogen storage sizing & CAPEX

Estimate compressed storage volume, compressor duty, and benchmark CAPEX against other storage approaches.

Compressed storage snapshot

Vessel volume
0.00 m³
Gas density
0.00 kg/m³
Charge time
—
Vessel CAPEX
—
Compressor power
—
Compressor CAPEX
—

CAPEX comparison

Costs reflect order-of-magnitude equipment values in 2025 USD and exclude civils, permitting, and balance-of-plant.

Hydrogen quality targets under ISO 14687

Check your calculated dew point and impurity levels against the typical limits below. The figures reference ISO 14687:2019 and related application guidance.

Fuel cell vehicles (ISO 14687 Grade C)

  • Minimum purity: 99.97% (≤300 ppm(v) total impurities)
  • Moisture limit: ≤5 µmol/mol (~-73 °C dew point @ 1 bar)
  • Key contaminants: H2O, CO, H2S, hydrocarbons, NH3, particulates
  • Related standards: ISO 19880-1 (refuelling), SAE J2601/J2719 sampling protocols

Stationary fuel cells (ISO 14687 Grade D)

  • Minimum purity: 99.9% (≤1000 ppm(v) total impurities)
  • Moisture limit: ≤10 µmol/mol (~-68 °C dew point)
  • Focus species: H2O, CO, H2S, total sulphur, halogenated compounds
  • Complementary guidance: ISO 22734 for onsite generation, ISO 19880-8 analysis

Industrial & heat applications (ISO 14687 Grade A)

  • Minimum purity: 99.5% (≤5000 ppm(v) total impurities)
  • Moisture limit: ≤50 µmol/mol (~-47 °C dew point)
  • Typical users: metallurgy, glass, refining, combustion support
  • Accept higher N2/Ar/CH4 content but monitor particulates & sulphur

Need deeper analysis?

Our engineers build detailed mass balances, compression sizing, and moisture management studies for hydrogen production facilities.

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