How It Works
A complete guide to personal cashflow forecasting with our free calculator.
What is Cashflow Forecasting?
Cashflow forecasting is the process of estimating the flow of money into and out of your accounts over a future period. It helps you understand when money will arrive, when bills are due, and what your balance might look like at any point in time.
For individuals and households, cashflow forecasting can help answer questions like: Will I have enough to cover rent next month? When is the best time to make a large purchase? How long until I reach my savings goal?
Our calculator simplifies this process by letting you input your income sources and expenses, then projecting your balance month by month. You can create multiple scenarios to see how different situations might affect your finances.
Getting Started
Step 1: Set Your Starting Point
Enter your current account balance and choose your base currency. This is the foundation for all calculations.
- Use your actual bank balance for accuracy
- Choose the currency you think in for daily expenses
Step 2: Choose Your Forecast Period
Select the start and end months for your forecast. You can project anywhere from a few months to several years ahead.
- Start with 6-12 months to get meaningful insights
- Longer forecasts become less accurate due to unknowns
Step 3: Add Your Income
Add all sources of income including salary, freelance payments, rental income, or any regular money coming in.
- Use gross or net amounts consistently
- Set the correct frequency (monthly, yearly, one-time)
Step 4: Add Your Expenses
List all your expenses from rent and utilities to subscriptions and variable spending categories.
- Don't forget annual expenses like insurance
- Group small expenses into categories for simplicity
Step 5: Create Scenarios
Use Best, Base, and Worst case scenarios to model different possibilities and prepare for uncertainty.
- Adjust amounts between scenarios to reflect risk
- Worst case helps you plan for unexpected situations
Step 6: Review and Adjust
Look at the charts and monthly breakdown to spot potential cash shortfalls or opportunities.
- Pay attention to months with negative balance
- Use 'Already paid' to track current month accurately
Key Features Explained
Multi-Currency Support
If you earn or spend in different currencies, you can enter items in their original currency. The calculator converts everything to your base currency using exchange rates you can customize. This is helpful for expats, remote workers, or anyone dealing with multiple currencies.
Scenario Comparison
Life is uncertain. The scenario feature lets you model three versions of your forecast: Best case (everything goes well), Base case (your expected situation), and Worst case (if things don't go as planned). Compare them side by side to make better decisions.
Flexible Frequencies
Not all income and expenses are monthly. Enter yearly items (like annual insurance), one-time items (like a tax refund), or custom schedules for irregular payments. The calculator spreads or places them correctly in your timeline.
Payment Tracking
Use the 'Already paid this month' toggle to mark items that have already been processed. This keeps your current month projection accurate without needing to delete and re-add items each month.
Card vs Account Expenses
Track credit card spending separately from direct account debits. This helps you understand your actual cash position versus what's on your card balance. Add a monthly 'Credit card payment' item to model paying off your card.
Export to CSV
Download your forecast data as a CSV file to open in spreadsheets like Excel or Google Sheets. This lets you do further analysis, create charts, or archive your projections for future reference.
Common Use Cases
Monthly Budget Planning
Freelancer Cash Management
Planning a Large Purchase
Managing Seasonal Expenses
Expat or Remote Worker
Emergency Fund Planning
Understanding Your Results
After entering your data, you'll see several ways to understand your cashflow:
Summary Cards
Quick overview showing total income, total expenses, net change, and ending balance for each scenario. This gives you the big picture at a glance.
Balance Trend Chart
A line chart showing how your balance changes month by month. An upward trend means you're saving; a downward trend means you're spending more than you earn.
Scenario Comparison Chart
Compare all three scenarios (best, base, worst) on a single chart. The spread between lines shows how much uncertainty exists in your forecast.
Monthly Breakdown Table
Detailed month-by-month view of income, expenses, and balance. Useful for identifying specific months that need attention.
Best Practices for Accurate Forecasts
Be Honest About Expenses
It's tempting to underestimate variable spending. Track your actual spending for a month before forecasting. Include small daily purchases that add up.
Update Regularly
Review and update your forecast monthly. Mark items as paid, adjust amounts if reality differs from predictions, and extend your forecast period as time passes.
Use Realistic Scenarios
Your 'best case' should be achievable, not fantasy. Your 'worst case' should be survivable, not catastrophic. Base case should reflect your most likely situation.
Don't Forget Irregular Items
Annual insurance, car registration, holiday gifts, medical co-pays, home repairs. These infrequent expenses can surprise you if not planned for.
Consider Timing
A payment due on the 1st vs the 15th can affect whether you have sufficient balance. Use the payment day feature and 'as of' date to model timing accurately.
Start Simple, Add Detail Later
Begin with your major income and expense categories. Once you understand the basic picture, add detail where it matters most.
Understanding Limitations
This tool is designed for educational exploration and personal budgeting. It has important limitations:
- Results are estimates based on your inputs and assumptions. Actual results will differ.
- The tool does not account for taxes, investment returns, loan interest calculations, or inflation over time.
- Exchange rates are approximate and should be adjusted to match your actual bank rates.
- Longer forecasts (beyond 12 months) become increasingly uncertain.
- This is not a substitute for professional financial advice. Consult qualified advisors for important financial decisions.
Frequently Asked Questions
Is my data stored on your servers?
No. All data is stored locally in your browser using localStorage. We never see or store your financial information. You can clear it anytime through your browser settings.
Can I save my forecast and return later?
Yes. Your forecast is automatically saved in your browser. When you return to the site on the same device and browser, your data will still be there.
How accurate are the exchange rates?
The default rates are approximate and for reference only. You should adjust them in the Exchange Rates section to match the rates your bank or FX provider offers.
Can I share my forecast with someone?
You can export your data to CSV and share the file. We don't have accounts or sharing features since all data stays local to your browser.
Why do my numbers look different from my bank?
Bank statements show transactions that have cleared. This forecast shows expected future cash flows based on your inputs. Timing differences, pending transactions, and estimates all create differences.
Is this suitable for business use?
This tool is designed for individual personal budgeting. Businesses have different needs including invoicing, accounts receivable/payable, tax obligations, and reporting requirements that this tool doesn't address.
Ready to Try It?
Open the calculator and start exploring your cashflow scenarios.