What Shock Survival Calculates
How long your loan payments survive after a one-time emergency empties a chunk of savings.
Shock Survival answers one question: if the emergency hit today, how many months of debt service are left in the tank?
An emergency is not the cost of the emergency — it's what happens to the bills that were already due. Shock Survival takes three numbers — liquid savings, a monthly loan payment, and the shock expense — and returns the months of debt service that remain. Under 3 months is the conventional high-default-risk band.
Quick answer
Shock Survival answers one question: if the emergency hit today, how many months of debt service are left in the tank?
Key points
- ▸ Formula: Survival = (Savings − Shock) ÷ Monthly Payment. Pure buffer math — income is assumed gone too.
- ▸ Liquid savings means accessible cash: checking, savings, high-yield, money market. Not retirement, not home equity.
- ▸ Monthly Payment is total debt service you can't defer — mortgage, auto, student loans, minimum credit-card payments.
- ▸ Shock Expense is the one-time event: ER visit, HVAC replacement, roof, legal retainer, funeral, lost deposit.
- ▸ Under 3 months triggers the critical band because most lenders begin collections action at 90 days past due.
- ▸ Zero-out income for worst-case. If income continues through the shock, add it to savings and re-run.
Examples
- $18k savings, $1,400/mo debt, $3,500 shock($18,000 − $3,500) ÷ $1,400 = 10.4 months. Stable band — time to refill the buffer without panic.
- $10k savings, $1,800/mo debt, $6,000 shock($10,000 − $6,000) ÷ $1,800 = 2.2 months. Critical — negotiate forbearance before month 3.
- $5k savings, $900/mo debt, $8,000 shockNegative — the shock alone exceeds savings. Survival = 0. Skip to Bill Triage and Default Optimizer today.
When to use which tool
- CYAN · STABLE — > 6 months of debt service after shock — stable, refill at normal pace.
- GOLD · GUARDED — 3-6 months post-shock — watch band, pause discretionary spend and rebuild buffer.
- MAGENTA · CRITICAL — < 3 months post-shock — critical, negotiate forbearance before collections hit.
Related
- Shock SurvivalHow many months of debt service survive an unexpected shock expense. Critical warning under 3 months.
- When to Stress-Test for a ShockSix moments where running the Shock Survival number changes the next decision.
- Five Shock Survival MistakesThe errors that make the buffer look bigger than it is.
Frequently asked questions
› What if income continues through the shock?
Add the continuing net income (after tax) to savings for the months you expect it, then run the math. Shock Survival's default is the worst case: shock + income loss. Most real shocks are one or the other, not both.
› Does this replace an emergency fund calculation?
No. An emergency fund is built proactively (3–6 months of expenses). Shock Survival is reactive — it tells you what the existing buffer will absorb when something actually hits.
› Why not include credit available? Troubleshooting
Because credit is not a buffer — it's the next month's bill at a higher rate. Tapping credit to cover a shock extends the runway by weeks and shortens it by years.
› How should I use a decision framework in real life? How-to
Use a decision framework to expose the tradeoff, not to outsource the decision. Write down the inputs, compare the output with your constraints, then ask what would change the answer. The strongest use is scenario testing: base case, conservative case, and failure case.
› Is this financial, legal, or tax advice? Trust & accuracy
No, this is not legal, financial, tax, medical, or professional advice unless the page explicitly says that use case is supported. It organizes assumptions so you can inspect them. Verify high-stakes choices with qualified people who can review facts, contracts, regulations, and downside risk.