FL-150 monthly averages from bank statements

Published October 27, 2026

California's Income and Expense Declaration, form FL-150, asks for most figures as monthly amounts. For income, item 5 gives the method in its own words: "For average monthly, add up all the income you received in each category in the last 12 months and divide the total by 12." This guide walks through that arithmetic, and the expense side in item 13, using your bank and card statements. It is general information, not legal advice. The form controls, and a lawyer or your court's free self-help center can answer questions about your own case.

What you need before you start

• Statements for every account you use: checking, savings and credit cards, covering the same 12 months.
• Your pay stubs. Item 5a asks for salary or wages "gross, before taxes". A paycheck deposit in your bank account is net pay, after taxes and deductions, so the deposit and the gross figure are different numbers. The form also asks you to attach pay stubs for the last two months.
• Somewhere to add things up: paper, a spreadsheet (see doing it in a spreadsheet), or software.

Step 1: check that each statement is all there

Every statement prints an opening balance and a closing balance. The opening balance, plus deposits, minus withdrawals, equals the closing balance. If your list of transactions does not reproduce the closing balance, a page or a row is missing. Find it before you average anything: an average built on a missing page is off by whatever was on that page.

Step 2: sort every transaction into a form line

Give each transaction one of the FL-150's own lines. Income goes to item 5, for example 5b overtime or 5c commissions or bonuses. Expenses go to item 13: 13d groceries and household supplies, 13e eating out, 13f utilities, 13l auto expenses and transportation, and so on. The item 13 guide lists every line in the form's wording.

Some transactions are neither income nor expenses:

• Transfers between your own accounts. Moving $300 from checking to savings shows up twice, once going out and once coming in. See transfers between your own accounts.
• Credit card payments. When the card's own statements are in your set, the purchases are already counted there, and the payment from checking is the same money a second time. See credit card payments versus purchases.
• Refunds. A $60 refund from a store is money coming back, not income. Netted against the category of the original purchase, it lowers that line.

Other items need a decision that only you can make: a large one-off purchase, money from a relative, loan proceeds, a bill someone else paid for you. The form has places for some of these, such as item 8 for one-time money and item 13s for expenses paid by others. Which line, if any, an item belongs on is your call. If you are unsure, ask a lawyer or the self-help center.

Step 3: total each line by month, then divide

For each line, add up its transactions month by month, add the months together, and divide. One line worked through:

For income, item 5 sets the period: the last 12 months, divided by 12. Item 13's heading says "Average monthly expenses" and does not name a period. Whatever period you add up, divide by the number of months in it, and keep a note of which months they were.

Bills that do not come every month

Car insurance paid every six months, an annual membership, a school fee paid twice a year: over 12 months each appears once or twice. Adding the whole year and dividing by 12 spreads them evenly. Insurance of $540 paid twice a year is $1,080 a year, or $90.00 a month. Looking at a single month instead would show either $0 or $540.

Item 13's three boxes

At the top of item 13 are three checkboxes: "Estimated expenses", "Actual expenses" and "Proposed needs". Statements record what was actually spent. Which box describes your figures is your decision. If your situation changed during the year, see last month versus average monthly and item 9 of the form, "Change in income".

Keep the working

You sign the FL-150 under penalty of perjury, and the other side may ask where a number came from. A short schedule for each line, listing the months and the transactions behind each total, answers that on one page.

Financial Affidavit Numbers does these steps in your browser: it reads PDF, CSV and OFX statements, checks that each one reconciles, sorts transactions into the FL-150's lines for you to confirm, and gives a worksheet of monthly averages with a schedule behind every figure. It does not fill in the FL-150; you copy the numbers onto the court's form.

Common questions

How do you calculate average monthly income on the FL-150?

Item 5 gives the method: add up all the income you received in each category in the last 12 months and divide the total by 12. Do it separately for each line, such as salary, overtime and bonuses. Lines 5a and 5b ask for gross amounts, before taxes.

Can I use bank statements to work out my FL-150?

You can work figures out from them. The form itself asks you to attach pay stubs for the last two months and proof of any other income, not bank statements. Paycheck deposits are net of taxes, so the gross wage figure in item 5a comes from pay stubs.

Do I divide FL-150 expenses by 12?

Item 13 asks for average monthly expenses but does not name a period. The arithmetic is the total for the months you added up, divided by the number of those months. Keep a note of which months you used.

What is the FL-150 form?

California's Income and Expense Declaration, Judicial Council form FL-150, revised September 1, 2024. It covers income, deductions, expenses, some assets and the people in your household, and you sign it under penalty of perjury. It is used in support and fee requests and in divorce disclosure.

More guides: How many bank statements for the FL-150 · FL-150 item 13, line by line · FL-150 last month vs average monthly · FL-150 vs FL-142 · When the FL-150 is filed or served · Florida short form vs long form · Florida: weekly and biweekly to monthly · Florida financial affidavit, section by section · Florida financial affidavit deadline · Credit card payments vs purchases · Transfers between your own accounts · Irregular income on a financial affidavit · Financial affidavit tools compared · A financial affidavit in a spreadsheet