Business Financial Cushion: How Much to Keep in Reserve — and How to Calculate It

One slow month. A client who pays three weeks late. A tax bill you forgot was coming. Any of these can happen in isolation and you barely notice. When two land in the same week — and there's nothing in reserve — that's when an owner starts borrowing from one supplier to pay another.

A financial cushion is what keeps that week boring instead of terrifying. It's not about being cautious for the sake of it. It's the difference between making decisions from a position of strength and making them in a panic at 11 p.m.

The problem is that most owners either keep no reserve at all, or keep a vague "some money on the account" and call it a cushion. Neither survives a real bad month. Here's how to size a reserve properly, where to keep it, and how to build one even if cash is tight right now.

What a cushion is — and what it isn't

A financial cushion is money set aside to cover your fixed costs when income drops. That's the whole job: to buy you time. Time to fix a slow month, replace a lost client, or wait out a seasonal dip — without firing people or skipping payments.

Three things it is not:

• It's not your account balance. The money sitting on your account right now includes client advances, money owed to suppliers, and next week's payroll. Most of it is already spoken for.
• It's not profit. Profit is a result you can spend or reinvest. The cushion is untouchable by design — the moment you dip into it for "an opportunity," it stops being a cushion.
• It's not one number forever. As your fixed costs grow, the reserve has to grow with them. A cushion sized for last year's business is too small for this year's.

The clearest way to think about it: the cushion answers one question — "If income stopped tomorrow, how long could I keep the lights on?"

How much to keep: the formula

The reserve is measured in months of fixed costs, not in a round sum. So the first step is knowing your monthly fixed costs — rent, salaries, subscriptions, everything that shows up whether you sell zero or a hundred.

Then multiply by the number of months you want to be able to survive:

An example. Your fixed costs are 150,000 a month. Income is fairly stable, so you aim for three months: 150,000 × 3 = 450,000. That's your target cushion. Not because 450,000 is a nice number — because it's exactly three months of keeping the business alive with no sales at all.

Notice what this does. It turns a scary, abstract worry ("do I have enough saved?") into a concrete target you can measure progress against.

"For years my 'reserve' was however much happened to be on the account. The first time I calculated it as months of fixed costs, I realised I had eleven days of runway, not the two months I imagined."

Where to keep it (not on your main account)

A cushion mixed into your operating account isn't a cushion — it's just a bigger balance you'll spend without noticing. The whole point is separation.

Keep the reserve on a separate account, ideally one that isn't one tap away in the same app you use for daily payments. Two rules make it work:

• You only see the operating money day to day. The reserve is out of sight, so you don't quietly lean on it.
• Moving money out of it is a deliberate decision, not a reflex. If taking from the cushion feels like a small event, you'll only do it when it's truly needed.

How to build one when cash is tight

"Set aside three months of costs" is easy to say when you have it. When you don't, the reserve gets built the same way any habit does — small and automatic, not in one heroic transfer.

• Pay the cushion like a supplier. Decide on a fixed percentage of every incoming payment — even 5% — and move it to the reserve the day the money lands, before it blends into the account.
• Bank the strong months. Seasonal businesses make the mistake of spending a great month as if every month will be great. The surplus from May is exactly what covers July.
• Start with one month, not three. One month of fixed costs already changes how you sleep. Hit that, then keep going.

The percentage matters less than the automation. A reserve that depends on you "remembering to save what's left over" never gets built — there's never anything left over.

How this works in Finmap

The hard part of a cushion isn't the transfer — it's knowing your real fixed costs and seeing the reserve separately from operating cash. That's exactly what Finmap does.

Connect your accounts and expenses sort themselves into categories, so your fixed costs are visible as one clear number — the number your cushion is built on. Keep the reserve on a separate account and Finmap shows it apart from operating money, so you always know two things at a glance: how much runway you have, and whether you're still on track to your target.

No spreadsheet to update, no guessing at month-end. Just a clear answer to "how long could we last" — on any given day.

📌 See exactly how many months of runway your business has. Try Finmap free for 14 days: connect your accounts, see your real fixed costs in one number, and keep your reserve separate from operating cash — so a bad month stays boring.

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