Emergency Fund: How Much You Actually Need and Where to Keep It

Why the generic rule doesn't fit everyone

"Save 3 to 6 months of expenses" is the most repeated piece of personal finance advice, and it's a reasonable starting point — but it ignores the two things that actually determine how much of a buffer you need: how quickly your income could stop, and how long it would take to replace it.

A tenured civil servant with a working spouse and no dependents has a very different risk profile than a sole-income freelancer with two children. Treating them the same way leads to either an underfunded safety net or money sitting idle that could be invested.

The two variables that set your target

To calculate a number specific to you, consider:

1. Income replacement time — how long would it realistically take to replace your income if you lost it? A specialized, in-demand role might take 1–2 months. A niche role in a small job market might take 6–12 months.
2. Expense flexibility — how much of your monthly spending is truly fixed (rent, loan payments, insurance) versus flexible (discretionary spending you could cut immediately)?

Multiply your realistic replacement time by your essential monthly expenses (not your total spending) to get a target that reflects your actual risk, rather than a generic multiple.

Worked example

Someone with:

• Essential monthly expenses: €2,200 (rent, utilities, groceries, insurance, minimum loan payments)
• Estimated time to replace income: 4 months (stable industry, moderately in-demand skills)
• Single income household with one dependent

Target emergency fund: €2,200 × 4 = €8,800, with a case for rounding up to 5–6 months (€11,000–€13,200) given the dependent and single income source.

Compare this to a dual-income household with no dependents and in-demand skills, where 3 months of essential expenses might be genuinely sufficient — a much smaller number.

What counts as an "essential" expense

Be strict here. Essential expenses are the ones that continue regardless of income:

• Rent or mortgage payment
• Utilities and basic groceries
• Insurance premiums
• Minimum debt payments
• Transport needed to look for work

Leave out subscriptions, dining out, travel, and other discretionary spending — in a genuine emergency, these get cut first, and including them inflates your target unnecessarily.

Where to actually keep the money

An emergency fund has one job: to be accessible without loss of value when you need it. That rules out investing it in stocks, where a market downturn could coincide with the exact moment you need to withdraw (job losses often cluster during recessions, which is also when markets fall).

Reasonable options, roughly in order of typical preference:

• High-yield savings account — instant or near-instant access, some interest, no risk of capital loss
• Money market fund — slightly better returns, still highly liquid, minimal risk
• Short-term fixed deposits (laddered) — only if you keep a portion fully liquid and ladder the rest so some is always maturing

Avoid: stocks, long-term bonds, property, or anything that can't be converted to cash within a few days without a loss of value.

Building the fund without stalling other goals

You don't need to hit your full target before investing elsewhere. A common approach: build 1 month of expenses quickly as a first buffer, then split further savings between the emergency fund and other goals (investments, pension) until the full emergency target is reached — after which all surplus can go to longer-term growth.

In MyRunway, you can model your emergency fund as its own financial item with a savings goal and track its growth alongside your other scenarios — seeing exactly which month you'll hit your target based on your actual monthly surplus.