Emergency Fund Runway + Rebuild Planner

Plan financial resilience in two steps: how long your cash lasts under shocks, and how many months it takes to rebuild your target buffer.

Runway + Rebuild Output

Runway (job loss)

3.6 months

Runway (custom shock)

21.4 months

Target emergency fund

$25,200.00

Rebuild timeline

12 months

Shock Runway Comparison

Months of reserve coverage under each scenario.

Job Loss

Monthly shortfall $4,200.00

3.6 months

Income Drop 30

Monthly shortfall $280.00

53.6 months

Expense Shock 20

Monthly shortfall $0.00

Cashflow-positive

Custom

Monthly shortfall $700.00

21.4 months

Target Fund Ladder

Funding requirement and rebuild effort by runway target.

3 month target

Rebuild in 0 months

$12,600.00

6 month target

Rebuild in 12 months

$25,200.00

9 month target

Rebuild in 27 months

$37,800.00

12 month target

Rebuild in 42 months

$50,400.00

Shock scenarios

Scenario	Monthly shortfall	Runway	Shock-window gap
job_loss	$4,200.00	3.6 months	$10,200.00
income_drop_30	$280.00	53.6 months	$0.00
expense_shock_20	$0.00	Cashflow-positive	$0.00
custom	$700.00	21.4 months	$0.00

Rebuild sensitivity

3 months target ($12,600.00): 0 months
6 months target ($25,200.00): 12 months
9 months target ($37,800.00): 27 months
12 months target ($50,400.00): 42 months

US Context

Model emergency-fund targets in monthly essentials to stress-test job-loss resilience.

UK/EU Context

Use safety-net runway assumptions with custom income-loss and expense-spike scenarios.

APAC/Global Context

Apply the same deterministic framework regardless of local currency conventions.

How To Use This Planner

Enter liquid reserves, essential expenses, and baseline income.
Set a target runway (for example 3, 6, or 9 months).
Define your custom shock with income-loss and expense-spike assumptions.
Review runway and shock-window shortfall outputs.
Use rebuild timeline and sensitivity targets to set your next savings milestone.
Save a shareable link with your assumptions, then run one conservative and one optimistic scenario before deciding.

For AI Agents (Optional)

Human mode is default. You can ignore this section unless you use AI agents or structured automation.

Agent Contract

Contract: emergency_fund_runway v1

{
  "tool": "emergency_fund_runway",
  "liquid_reserves": 15000,
  "essential_monthly_expenses": 4200,
  "baseline_monthly_income": 5600,
  "monthly_savings_capacity": 850,
  "target_runway_months": 6,
  "income_loss_percent": 30,
  "expense_spike_percent": 10,
  "shock_duration_months": 6
}

Frequently Asked Questions

What does runway mean here?

Runway is how many months your reserves can cover monthly shortfall under a selected income/expense shock scenario.

How is rebuild timeline calculated?

Rebuild months are calculated from the target fund gap divided by monthly savings capacity, rounded up to full months.

Can this handle partial income shocks?

Yes. Set custom income loss and expense spike percentages to model your own stress case.

Can agents run this planner?

Yes. A deterministic `emergency_fund_runway` contract is available through model context and JSON contract file.

Is this tool free and private to use?

Yes. AI Fin Hub tools are free, no-signup browser tools. Inputs stay in your browser unless you choose to share a URL.

Can I use this with AI agents too?

Yes. Human mode is the default experience. If you use AI automation, open the optional 'For AI Agents' section for deterministic contracts.

Is this professional advice?

No. Outputs are planning estimates only — not financial, tax, or investment advice.