How to Create a Cash Flow Forecast in 5 Steps

Why Every Business Needs a Cash Flow Forecast

A cash flow forecast projects your expected inflows and outflows over a future period, typically 30 to 90 days. Unlike historical financial statements that tell you what happened, a forecast tells you what is likely to happen. This forward-looking view gives you time to prevent shortfalls and make confident spending decisions.

Many business owners avoid forecasting because it seems complicated. In reality, a useful cash flow forecast can be built in five straightforward steps without advanced accounting knowledge.

Step	Action	Key Output
1	Determine starting cash balance	Baseline number
2	Estimate cash inflows	Expected receipts by date
3	Estimate cash outflows	Expected payments by date
4	Calculate net cash flow	Surplus or shortfall per period
5	Review and update regularly	Living forecast document

Step 1: Determine Your Starting Cash Balance

Begin with the amount of cash currently available in all your business bank accounts. Check operating accounts, savings, and any petty cash funds. Record this balance as of a specific date, typically the first day of your forecast period.

Step 2: Estimate Cash Inflows

List all expected sources of incoming cash for each week or month in your forecast period.

Customer payments: Based on current invoices outstanding and their payment terms.
Expected new sales: Adjusted for your typical collection timeline.
Other income: Interest, refunds, tax credits, loan proceeds, or investment income.

Be conservative with estimates. If a customer typically pays 10 days late, factor that into your timing.

Step 3: Estimate Cash Outflows

List every expected payment by the date it will leave your account:

Fixed costs: Rent, loan payments, insurance, subscriptions — predictable and easy to forecast.
Variable costs: Inventory, raw materials, shipping, utilities — base on historical patterns.
Payroll: Salaries, wages, benefits, and payroll taxes including your own compensation.
One-time expenses: Equipment purchases, tax payments, annual renewals, or planned investments.

Step 4: Calculate Net Cash Flow

For each period, subtract total outflows from total inflows. Then add the net cash flow to your starting balance to determine the ending balance.

The formula is simple: Starting Balance + Inflows - Outflows = Ending Balance. That ending balance becomes the starting balance for the next period. Any period where the ending balance drops below zero signals a potential cash shortfall.

Key Takeaway: A forecast is a living document — compare projections to actual results weekly. Over time, your estimates become more accurate as you learn how your business actually behaves.

Step 5: Review, Adjust, and Update Regularly

Compare your projections to actual results weekly. When reality differs from your forecast, adjust future projections accordingly. Pay special attention to the assumptions behind your numbers.

If a client has not paid on time, update the forecast immediately. If a new expense arises, add it in. Regular updates transform your forecast from a static document into a dynamic management tool.

Tools to Simplify Cash Flow Forecasting

While a spreadsheet works for basic forecasting, platforms like Finntree can automate much of the process by analyzing historical transaction data and generating projections based on actual patterns. This eliminates manual data entry and reduces errors.

As your forecasting skills develop, explore more advanced techniques in our guide to advanced forecasting techniques. You can also learn how machine learning improves financial predictions to refine your forecasts over time.