The Starship Fleet Planner is a fast, first-order sizing model for anyone trying to reason about the scale of a Moon or Mars logistics campaign. Instead of guessing how many launches a program needs, you enter the payload you want on the surface, how many years you have, and a few vehicle economics, and the tool returns the fleet size, annual launch cadence, and rough capital cost.
It is deliberately transparent: every number comes from a handful of clearly stated assumptions you can adjust, so it is useful for students, educators, journalists, and mission planners who want a defensible back-of-the-envelope figure rather than a black box.
The core relationship is simple. The number of cargo ships needed equals the target payload divided by the payload per ship. That figure is then multiplied by one plus the refuel ratio to account for the tanker flights required to top off each departing vehicle, which dominate the flight count for high-energy destinations.
Launch cadence is the total flights spread evenly across your timeline, and total cost multiplies the flight count by the per-ship cost. Because reusable vehicles amortise hardware across many flights, the per-kilogram cost falls sharply as cadence rises — the same dynamic that makes a large, busy fleet cheaper per tonne than a small one.
Delivering 1,000 tonnes over 5 years with a refuel ratio of 4 and 100-tonne ships implies 10 cargo flights plus 40 tanker flights — about 50 flights, or roughly 10 launches per year, at an indicative cost near $5B at $100M per flight. Halving the refuel ratio nearly halves the fleet, which is why on-orbit and lunar propellant production changes the economics so dramatically.
No. It is an independent educational estimator that uses public, adjustable assumptions. It is not affiliated with SpaceX and does not use proprietary data.
High-energy departures need tanker flights to refill the vehicle in orbit. Those tankers can outnumber cargo flights several to one, so the refuel ratio is often the single biggest driver of total launches.
Yes — lowering the refuel ratio approximates propellant sourced from the Moon or orbit instead of Earth, and you will see the fleet and cost drop accordingly.
They are order-of-magnitude figures for comparison and teaching, not a budget. Treat them as a starting point for discussion, then refine with detailed models.
Yes. All computation runs in your browser with no server, and the interface is available in 25 languages.
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