Business Cash Buffer Calculator

Generic advice says a business should hold three to six months of costs, which is true and almost useless, because the difference between three and six months is usually the difference between an achievable target and an impossible one. This page builds the number from your own risk profile instead. It starts with what actually leaves the business each month whether or not revenue arrives, being fixed operating costs, payroll and debt repayments, then adjusts the months of cover upward for the things that genuinely lengthen how long you might have to self-fund: volatile revenue, seasonality, carrying staff, and customers who pay slowly. Payroll is treated separately because it is both the largest line in most small businesses and the least flexible, since suppliers can usually be asked to wait and employees cannot. The output is a target in months and in dollars, your current position against it, and the time required to close the gap at whatever you can realistically save. It also gives staged milestones, because a full target frequently takes years to reach and most of the protection arrives long before the final dollar does. Reaching one month of cover is a meaningful change in how much risk the business is carrying, and it is a far more useful goal than a number so distant it never gets started.

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Three To Six Months Is Not Advice

Every guide says hold three to six months of costs. The range is so wide as to be meaningless: on the worked example the difference between the two ends is $180,600.00 against $361,200.00, which is the difference between a stretching goal and one nobody starts.

The position within the range should come from how long the business might actually have to fund itself, and that depends on specific things. Volatile revenue means the bad month arrives without warning. Seasonality means you know it is coming but cannot avoid it. Staff mean the largest cost cannot be reduced quickly. Slow debtors mean money earned is not money available. This page adds those up rather than asking you to guess.

Worked Example: 5.5 Months, And Why

Monthly outflow is $60,200.00: $18,000.00 of fixed costs, $34,000.00 of payroll and $8,200.00 of debt repayments.

The target starts at 3.0 months. Medium volatility adds 1.0. Carrying staff adds 0.5. Seasonality adds 0.5. Debtors paying in 48 days, beyond the 45 day threshold, adds 0.5. That gives 5.5 months, or $331,100.00.

The business holds $95,000.00, which is 1.6 months, or 28.69% of target. The shortfall is $236,100.00, and at $4,000.00 a month it closes in 59.0 months.

Nearly Five Years Is Why Milestones Matter

A target reached in 2031 does not change how anyone behaves today. Staged milestones do.

One month of outflow, $60,200.00, is already held. That is not nothing: it means a single bad month does not require a phone call to the bank.

Three months, $180,600.00, is 21.4 months away. That is a real goal with a real date, and it is the point at which a quarter of disrupted trading stops being an emergency. Most of the practical protection a buffer provides is delivered by the time you reach it.

The full 5.5 months is the destination rather than the plan. Aim at the three month mark, then reassess, because by then the business will have changed anyway.

Payroll Is What Makes Buffers Large

Payroll is 56.48% of the monthly outflow on the worked example, and it is the reason the target is 5.5 months rather than 3.0.

The reason is flexibility, not size. Most suppliers will discuss timing if asked early and honestly. Rent can sometimes be renegotiated. Software can be cancelled. None of that applies to wages: they are due on the day, in full, and reducing them means notice periods, consultation and process that take weeks even when handled properly. A business with staff simply has a longer minimum reaction time, and the buffer exists to cover that period.

Our True Cost of Employee Calculator shows the full employer cost that belongs in the payroll figure, including KiwiSaver, ACC and ESCT.

What Is Not A Buffer

Three things routinely get counted and should not be.

GST and PAYE. That money belongs to Inland Revenue on a known date. Counting it produces a balance that looks healthy until the 20th, and spending it is the most common route into tax debt, where use of money interest compounds daily. Our IRD Instalment Arrangement Calculator shows what that costs once it happens.

An undrawn overdraft. A facility is a buffer until the bank reviews it, and reviews tend to coincide with the trading conditions that made you need it. Treat it as a second line behind actual cash.

Customer deposits. Money taken for work not yet done is a liability. If the work is cancelled it goes back.

Building It Faster

The saving rate is only one lever and usually the slowest. Reducing debtor days converts money you have already earned into money you can hold, and on most small businesses it is the largest single pot available: our Days Sales Outstanding Calculator sizes it. Reducing the outflow lowers the target itself, so every dollar off fixed costs is worth 5.5 dollars off the goal here. And restructuring debt frees monthly cash, though at a cost, which our Business Debt Restructure Calculator quantifies.

Once the buffer exists, test it. Our Business Stress Test Calculator shows how many months it actually buys at various levels of downturn, which is the question the buffer was built to answer.

Related NZ Business Cash Calculators

• Business Stress Test Calculator: how long this buffer lasts in a downturn.
• Cash Runway Calculator: months of cash at your current burn rate.
• Burn Rate Calculator: how fast the business consumes cash.
• Overtrading Risk Calculator: the cash growth will consume on top of this.
• Emergency Fund Calculator: the personal equivalent, held separately.
• Can I Afford to Hire?: the background to this calculation.
• Financial Buffers: background on this topic.