Startup Runway Shift Calculator

📖 Overview

Hiring changes burn profile and can shorten optionality fast.

This tool models baseline runway then a second burn phase after your hiring date.

Use it to test whether growth plans fit real cash constraints.

Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.

Compares current runway with a two-phase burn scenario that changes after a hiring milestone.

The Formula

Runway = Phase1 Months + Remaining Cash ÷ Post-Hire Burn

Phase1 Months	Months until hiring at current burn rate
Remaining Cash	Cash left after phase1 burn
Post-Hire Burn	New monthly burn after hiring/cost shift
Runway	Total months of survival under scenario

💡Runway should be paired with fundraising lead-time; survival to zero is not a safe operating target.

Cash	Current burn	Post-hire burn	Runway effect
$220k	$28k	$37k	Shortens runway materially
$350k	$30k	$36k	Moderate reduction
$500k	$40k	$46k	Manageable with revenue support
$180k	$25k	$35k	High survival risk

Use this tool when you need a fast decision during active planning or execution.
Use this before committing money, time, or tradeoffs that are hard to reverse.
Use this to compare options using the same assumptions across scenarios.

Results can be misleading if key inputs are missing, stale, or unrealistic.
Very small or very large values may amplify rounding effects and interpretation risk.
If assumptions change mid-decision, recalculate before acting.

💡 Model both optimistic and conservative hiring timing.

💡 Use this when testing “hire now vs later” tradeoffs.

💡 Keep an operating buffer beyond minimum survival runway.

❓ What if cash runs out before hiring month?

The model reports that failure mode explicitly.

❓ Can burn increase be negative?

Yes, if you expect cost cuts instead of increases.