Should I Quit My Job? Runway Calculator — Honest Months You Have

What This Calculator Does

The Should-I-Quit-Job Runway Calculator answers a brutally practical question: “If I quit, how many months can I actually fund myself before income returns?” Not the back-of-napkin version most blogs offer (savings ÷ monthly rent), but the honest one — with healthcare priced in (employer was paying it; now you are), severance counted, a confidence multiplier applied to your burn estimate (first- time quitters under-estimate by 25-30%), an emergency cushion reserved before counting runway, and any expected income while off subtracted from net burn.

It returns a runway in months, a verdict tier (STRONG GO / GO / TIGHT / RISKY / DON’T QUIT YET), and a concrete next-action recommendation. When the math is tight, it surfaces two levers — the dollar amount of expense cuts that would close the gap, and the dollar amount of side income that would tip break-even — so you know exactly what would flip the verdict. It's not a sermon. It’s the math you should run before pulling the trigger.

The Math

Two pieces of math you won’t see in most online calculators. First, the confidence multiplier applies to gross burn before anything else: high (×1.00) for honest spending visibility, medium (×1.15) for realistic, low (×1.30) for first-time quitters. The empirical literature on post-quit burn under-estimation supports those exact multipliers. Second, the cushion reserve is held back BEFORE counting runway— it’s untouchable emergency buffer for medical surprises or a job hunt running long. Counting it as runway means you’d technically be funded but with zero margin for the world being slightly worse than expected.

A Worked Example — Standard 12-Month Sabbatical

$50,000 liquid savings, $0 severance, $4,500/mo expenses, $800/mo healthcare (ACA marketplace post-subsidy), $0 expected income while off, 3 months cushion preference, medium confidence in burn (×1.15), 12-month target horizon.

• Gross burn: $4,500 + $800 = $5,300/mo.
• Adjusted burn: $5,300 × 1.15 = $6,095/mo.
• Cushion reserve: $6,095 × 3 = $18,285 held back.
• Effective savings: $50,000 − $18,285 = $31,715.
• Runway: $31,715 / $6,095 ≈ 5.2 months.
• Horizon ratio: 5.2 / 12 = 0.43 → RISKY verdict — significant gap; build runway first.
• Lever 1 (cut expenses): would need ~$1,800/mo trim to hit 12-month horizon.
• Lever 2 (earn while off): ~$3,800/mo would make runway effectively unlimited.

Compare with the naïve version most blogs run: $50,000 ÷ $4,500 = 11.1 months — “you have a year of runway, quit!” The honest version says 5.2 months once you price in healthcare, confidence buffer, and reserve cushion. That’s a 53% gap between the rosy and honest numbers, and it’s exactly the gap that lands first-time quitters in trouble at month 6.

Why Healthcare Is A Separate Input

Because in the US it’s the single biggest hidden cost that employer-paid coverage masks. A family of 4 on COBRA can pay $2,000+/mo for the same coverage that costs $0 in paycheck deduction terms while employed. ACA marketplace plans with subsidies run $300-1,500/mo. Knowing this number forces the conversation about what coverage you’ll choose and what it actually costs. UK / NHS users: healthcare = 0. India / private insurance: $100-300/mo. Outside the US, set this to your real local cost; the math doesn’t change.

Why The Cushion Comes Off The Top

The cushion (default 3 months at adjusted burn) is the untouchable emergency buffer. Medical surprise, family emergency, job-search running 4 months longer than expected, slow freelance ramp — any of these turn a tight runway into a credit-card spiral if you’ve already counted the cushion as spendable. The calculator deliberately reserves it first, so the runway number is what you can actually spend without burning the safety net. Conservative users push it to 6+; aggressive users drop to 0; the default 3 matches standard personal-finance recommendation.

Reading The Verdict Tiers

Verdicts are framed as next-actions, not labels. STRONG GO = math is comfortable, validate income stability. GO = workable, build a small buffer or trim. TIGHT = build 2-4 more months of runway OR commit to part-time income. RISKY = significant gap, aggressively save 6-12 more months. DON’T QUIT YET= the math is against you, pursue the goal in spare cycles while still employed. None of these are moral judgments; they’re staged action recommendations. The calculator's job is to honestly report where you sit on the staircase.

Common Mistakes

• Including 401(k) / IRA in “current savings.”The default healthy answer is don’t. Early withdrawal incurs a 10% penalty plus income tax — often 35%+ combined. Plus the opportunity cost of compounding lost. The calculator deliberately excludes retirement accounts to keep you honest about liquid runway. If you DO plan to tap retirement, run the math separately: net = balance × (1 − 0.10 − marginalTax).
• Crediting speculative freelance work as “expected income while off.”Only credit signed contracts or recurring income that’s been stable for 6+ months. “I think I can land freelance work” is not committed income. The math gets dishonest fast when hopeful future income gets counted as guaranteed; if you must include it, halve it.
• Picking high confidence as a first-time quitter. The empirical literature is clear — first-time quitters under-estimate burn by 25-30% on average. Bills you forgot exist (annual subscriptions, professional memberships), replacement costs for employer perks (gym, free lunches, kid activities), increased social spend from unstructured time. Pick LOW (×1.30) on your first sabbatical; you can always re-run after 3 months of real spending data.
• Using a horizon shorter than reality.A startup founder using horizon=12 months is typically delusional — most startups need 18-24 months of personal runway. A grad-school applicant using horizon=12 months forgets the year-long admissions cycle plus the program itself. Pick the horizon that matches what you’re actually trying to do; don’t shrink it to make the verdict tier prettier.
• Forgetting to negotiate severance.Most US severance is negotiable beyond the company’s opening offer — typical bumps are 2-6 weeks per year of tenure for non-executive roles. UK statutory minimum is 0.5-1.5 weeks/year. Even an extra month of severance can shift the verdict from TIGHT to GO. Always counter; ask for healthcare extension as part of the package.
• Skipping the partial-quit option.If full quit comes back RISKY, ask whether a 60% time / 60% pay arrangement works. Treat the 40% income gap as “expected income while off” (the new reduced income) and re-run at the lower expense base. Most employers say no, but a meaningful minority say yes when the alternative is full quit. Worth asking before triggering full unemployment.

Related Calculators

Run the Freelance Rate Calculator before quitting if you’re going freelance — set the rate that replaces your salary at parity BEFORE you quit, not after. Pre-quit, an aggressive sweep with the Budget Calculator often surfaces $200-500/mo of cuts that meaningfully extend runway. The Regret Minimization Calculator is the right tool when the question is “should I attempt this at all” rather than “can I afford to” — the two compose into a complete go-decision. The Take-Home Pay Calculator helps validate the income side of any partial-quit / consulting transition.