Cash Runway Calculator

Estimate how long available cash can support a business under current revenue and expense assumptions.

Runway inputs

Estimate how long cash can support a business at the current burn rate.

Runway

No depletion

Monthly net cash flow

$2,000

Safety months

3.2 months

Projected cash after 12 months

$127,157

Runway is a liquidity estimate. Recheck it whenever revenue, payroll, rent, debt service, or tax timing changes materially.

Related calculators

What is the cash runway calculator?

This calculator estimates how many months a business can keep operating with current cash, monthly revenue, and monthly expenses. It follows the Korean source concept of startup and small-business runway instead of reducing the page to a generic profit-rate estimate.

The guide separates gross burn from net burn, projects a 12-month cash path, and compares worst-case, current-trend, and optimistic scenarios. It is especially useful before hiring, ad spending, inventory purchases, or fundraising.

Core runway formula

Net burn = monthly expenses - monthly revenue. Runway months = cash on hand / net burn. If net burn is zero or negative, the business is cash-flow positive and runway is treated as effectively unlimited.

Burn-rate and safety logic

Monthly burn example

  • Gross burn means all monthly spending, including labor, rent, materials, ads, software, insurance, and loan payments.
  • Net burn is the cash loss after revenue. Monthly spending KRW 11,000,000 and revenue KRW 8,000,000 means net burn is KRW 3,000,000.
  • With cash KRW 50,000,000 and net burn KRW 3,000,000, runway is about 16.7 months.
  • The 12-month simulation can apply revenue growth and expense increases so seasonal or scaling risk is visible before cash becomes tight.

Scenario and buffer interpretation

  • Worst case applies a 30% revenue drop, realistic case follows the current trend, and optimistic case applies a 20% revenue increase.
  • Safety margin = cash / three months of operating cost.
  • Under 1x is danger, 1x to 2x is caution, 2x to 3x is safe, and 3x or more means there is surplus cash capacity.
  • For IT and software startups, the Korean source recommends 12 to 18 months of runway because Series A fundraising can take 6 to 12 months.

Industry assumptions and 2026 support

Business-model differences

  • Food service has high daily sales volatility. Off-season months such as January, February, and August can reduce sales by 30% to 40%.
  • Food service cost references include material cost at 30% to 40%, labor at 25% to 35%, and rent at 15% to 20%.
  • Online stores often carry ad spend at 15% to 25% of revenue, platform fees around 10% to 15% for marketplaces, and card or own-mall fees around 2% to 3%.
  • Beauty, nail, academy, and other service businesses have low material cost but high fixed cost, and need roughly 70% or higher capacity utilization.
  • IT and software startups can have labor at 60% to 80% of cost while early revenue is still low.

Cash management and support programs

  • 2026 policy-fund references include small-business policy funds up to KRW 100,000,000 at about 2% to 3.5% interest.
  • Emergency management stability loans are referenced up to KRW 70,000,000, along with consulting support and tax-payment deferral options.
  • Eligible new hires may receive up to an 80% reduction in the four major social-insurance burden.
  • Operational practices include separate business accounts, a weekly Friday cash review, reserving 10% to 15% of peak-season sales for off-season months, quarterly fixed-cost review, and active receivables management.