Estimate spacecraft propellant from dry mass, required delta-v, specific impulse, and a selectable contingency. Although listed with satellite power planning tools, this calculation focuses on the propulsion mass that competes with batteries, arrays, and payload for the spacecraft mass budget.
Ideal wet mass = dry mass × exp(delta-v ÷ (specific impulse × standard gravity)). Ideal propellant = wet mass − dry mass. Loaded propellant = ideal propellant × (1 + contingency).
Treat the main result as an engineering estimate based on the stated inputs. Compare it with the applicable mission requirement and retain enough traceability to update the result when assumptions change.
This calculator supports early trade studies and does not replace mission-specific simulation, environmental analysis, or professional engineering review.
For 500 kg dry mass, 250 m/s delta-v, and 220 s specific impulse, ideal propellant is about 61.43 kg. A 10% contingency raises the loaded amount to about 67.57 kg.
It uses the values shown in the input panel and the formula stated on this page. It does not add hidden operational or environmental allowances.
Yes. Decimal values are accepted within each field’s displayed range, and calculations retain precision until the result is formatted.
Use a value justified by your project’s maturity, uncertainty policy, and verification plan rather than treating the default as a universal recommendation.
No. It is a first-pass estimate for trade studies. Verify the design with subsystem models, test data, and mission-specific constraints.
Zero is accepted where it represents a physically meaningful absence of load, loss, background, duty, or maneuver demand. Inputs used as divisors must remain above zero.
| Item | Use |
|---|---|
| Primary inputs | Enter values in the units printed beside each field. |
| Margin or reserve | Applied only where stated in the formula. |
| Displayed result | Rounded for readability; internal math keeps full precision. |