The rocket equation

Enter values for 3 of the variables and press calculate on the remaining one. (Note that I use the more popular specific impulse with isp = ve / 9.8)

Alternatively, you can set delta-v, isp, and the stage parameters to do a fixed point calculation of a stage dry mass. (inert mass ratio = dry mass / propellant mass)

dv m/s
isp s
m0 kg
m1 kg
inert mass ratio
payload mass
dry mass