Cash Burn Rate Calculator

What is cash burn rate?

Cash burn rate is how fast your company spends its cash reserves each month before you reach profitability or raise again. Founders who confuse gross spend with actual cash loss often think they have more time than they do. The number that matters for survival is net burn — expenses minus the cash revenue coming in — and how many months that leaves you at today's pace.

How to read every box in the cash burn rate calculator

Meet Jordan, who runs a bootstrapped SaaS tool. The bank holds $1.2M. Each month the team spends $150,000 on salaries, ads, and tools, and collects $70,000 from customers. Jordan uses this calculator before every board check-in — no spreadsheet gymnastics.

Inputs — what you type in

Cash balance

Money in the bank today — checking, savings, liquid treasury. Jordan has $1,200,000.

Monthly operating expenses

Total cash going out: payroll, rent, software, ads, contractors, support. Jordan spends $150,000. This is gross burn.

Monthly revenue (cash in)

Cash collected, not invoiced AR. Jordan brings in $70,000. Subtract this from gross burn to get net burn.

3-month average tab

Enter the last three months of expenses and revenue if one month was weird — annual prepay, a big hire, a launch spike. The calculator averages them so burn is not distorted by a single outlier.

Monthly support / CX cost

The slice of opex spent on customer service — agents, BPO, Zendesk seats. Jordan allocates $25,000. This powers the AI savings what-if without guessing at total company overhead.

AI cost reduction on support (%)

Models how much an AI agent could shave off support spend. At 25% on $25K, Jordan saves $6,250/month — a conservative midpoint of the 20–35% net savings range McKinsey and industry studies cite for AI-enabled service.

Outputs — what you get back

Net burn / month

The cash actually leaving each month. Jordan's is $80,000. Boards usually mean this when they ask “what’s your burn?”

Net runway

Cash ÷ net burn. Jordan has 15 months at current pace. Gross runway (ignoring revenue) would be only 8 months — useful worst case, wrong for planning.

Projected net burn & runway

After the AI support savings what-if. Shows extra months bought without pretending revenue magically doubles.

Charts

Cash balance declining month by month (current vs projected), plus runway sensitivity as support savings increase.

The problem: gross vs net burn confuses everyone

Saying “we burn $150K a month” without mentioning $70K in revenue makes the company look twice as sick as it is. Investors know the difference; founders sometimes do not. Carta defines gross burn as total monthly outflows and net burn as expenses minus revenue (Carta). Mercury puts it plainly: net burn is what you use for runway (Mercury).

Runway is not academic. Many teams aim for 12–18 months after a funding round and start the next raise at 6–9 months remaining, because closes often take 3–6 months (burn rate planning guide). Jordan at 15 months is healthy; at 5 months Jordan should already be in investor conversations.

The cash burn rate formula

Standard startup finance, same everywhere:

Gross burn = monthly operating cash outflowsNet burn = gross burn − monthly cash revenueRunway (months) = cash balance ÷ net burn

Example: $1.2M cash, $150K expenses, $70K revenue → net burn $80K → runway 15 months. If revenue stopped tomorrow, gross runway would be $1.2M ÷ $150K = 8 months — the worst-case floor.

“Net burn rate is the actual cash loss per month, calculated as total expenses minus revenue.”

How AI customer service lowers burn — with numbers

Burn rate moves two ways: cut costs or grow revenue. AI customer service does both, but the cost line is easiest to model in this calculator.

• McKinsey: AI-enabled self-service can cut incident volume 40–50% and cost-to-serve by 20% or more (Coworker AI roundup citing McKinsey).
• Avis: 39% support cost savings in 12 months with an AI assistant handling 70% of inquiries (Insider One case study).
• Per-ticket economics: AI-handled conversations often run $0.50–$2 vs $6–$13+ for human agents when resolution is real, not deflection (Fin.ai industry analysis).

Map it to Jordan: $25K support × 25% savings = $6,250/month off net burn. That is ~1.3 extra months of runway without a layoff or a fundraise. On the revenue side, faster support reduces churn — use our LTV calculator to dollarize retention and our NPS calculator to track whether customers still recommend you after support changes.

How ChatInCart helps you extend runway

ChatInCart is an AI customer service agent trained on your website and docs, embedded in minutes. It handles tier-one questions — order status, returns, pricing, setup — so your team is not hiring linearly with ticket volume.

For a team like Jordan's, that means:

• Lower gross burn — deflect repetitive tickets instead of adding a $4K–$6K/month agent seat for every support spike.
• Better net burn — happy customers renew; a 5-point retention lift can add tens of thousands in LTV per cohort (see the LTV tool).
• Fast payback — many AI service deployments pay back in 6–9 months on support cost alone; ChatInCart has a free tier to prove resolution quality before you scale spend.

Plug your support line item into the what-if above. If 25% savings buys another month of runway, the agent subscription is not a nice-to-have — it is balance-sheet math. Then re-run the calculator quarterly with a 3-month trailing average so the board sees a honest trend, not a lucky month.