# What is the equation to find how much fuel you need to reach a velocity? [closed]

Theoretically, I need to launch a rocket, and I need to find how much fuel I need to reach a velocity however I do not know the equation.

• I’m voting to close this question because of lack of prior research. At the top of any Space Exploration Stack Exchange window you'll see a "Search on Space Exploration..." field. Please search for "rocket equation", then "specific impulse", and finally "delta-V". When you are done please come back with more specific questions. Mar 8 at 16:18
• There is no way someone asking this question would be familiar with those search terms. Mar 16 at 2:01
• I would take down the question but the stack-exchange won't let me, but thanks for the help answering my question Mar 17 at 12:33

You need to use the rocket equation:

$$\Delta V = v_e \cdot \ln(\frac{m_0}{m_f})$$

Where $$\Delta V$$ is the change in velocity in m/s
$$v_e$$ is the rocket exhaust velocity in m/s
$$m_f$$ is the empty mass of the rocket
$$m_0$$ is the mass of rocket plus all propellants

This is available in various forms and can be mathematically rearranged to suit. Alternatively there are many calculators available online such as this one:

https://www.omnicalculator.com/physics/ideal-rocket-equation

Simply plug in some numbers and adjust to suit

• Thank you for the answer Mar 8 at 17:56
• @user46782 you can press the check mark on the answer to mark that it answered your question Mar 8 at 20:42