This guide shows you how to calculate your Vault amount using one simple formula, so bills stay safe and surprises stop breaking your month.
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If you want the full system first, start here: The VaultRule Two-Account System (Simple Version).
The Vault formula
Vault = Monthly bills + (Annual costs ÷ 12) + Buffer
Step 1: List your monthly bills
Only include must-pay costs (rent, utilities, insurance, debt, core essentials). If you’re unsure what belongs here, use: What counts as a bill (and what doesn’t).
Step 2: Add annual costs (annual ÷ 12)
This is where most people underfund Vault. Add anything that happens yearly (or most years) as annual ÷ 12.
Use the checklist: Annual Bills Checklist (Annual ÷ 12).
If you struggle with subscriptions, gifts, and repairs, use: Gray-zone expenses.
Step 3: Add a buffer
Start small: €50–€200. The buffer is what keeps the system calm when real life is messy.
Quick example
- Monthly bills: €1,400
- Annual costs: €1,200 → €100/month
- Buffer: €100
- Vault amount = €1,600
Next step: pay bills from Vault (not Flow)
Once you have your Vault amount, set bills to auto-pay from Vault so Flow stays clean. Use: Bills to auto-pay from Vault (checklist).
Next step: automate the transfer
After you calculate Vault, make it automatic on payday: Automate VaultRule on payday.
If your Vault still feels tight, use: VaultRule Mistakes (and Quick Fixes).
Disclaimer: This is educational content, not financial advice.
Sources and methodology
VaultRule’s framework is editorial guidance. The official resources below support the underlying practices of tracking bills, managing cash flow, monitoring accounts, and building reserves.
- Consumer Financial Protection Bureau — Bill Calendar
- Consumer Financial Protection Bureau — Your Money, Your Goals toolkit
- Consumer Financial Protection Bureau — Emergency savings and cash-flow guidance
Sources reviewed August 21, 2026. Product terms and consumer protections vary by provider and country; verify details before acting.