SaaS Magic Number Calculator
Measure how efficiently sales & marketing spend turns into new ARR.
$
$
$
Sales & marketing that produced this growth.Net new ARR
$800,000
Current − previous
Magic number
0.73×
Net new ARR ÷ prior S&M
Efficiency read
Acceptable
GTM efficiency
0.73× is workable but not efficient enough to floor it. Improve conversion and retention before scaling spend.
Rule of thumb: above ~0.75 you can invest confidently; below ~0.5 the model isn't ready to scale. It measures efficiency, not absolute growth.
About this calculator
Compare net new ARR against prior-quarter sales & marketing spend to get your SaaS magic number — the board-level read on whether it's time to pour on fuel or fix efficiency.
Everything runs in your browser — nothing you type is sent anywhere or stored. Use it to sanity-check a plan, pressure-test a channel, or brief a team before you commit budget.