Project 1: A simple budget

Okay, now we have enough tools to do our first, simple project: a budget.

Imagine you’re a person who is in a position where you need to keep track of where money goes. I imagine that this isn’t a very hard stretch for most people.

You probably want to know several things. You want to know how much money you have at any given time. You’ll want to know how much money has come in, and how much money has gone out. If you’re dealing with more than one account (if, for example, you have a credit card and a checking account, or you’re a library tracking spending in multiple departments), you’ll want to know which account the money is going to/from. And you probably want to know what the money came from or was spent on.

If you look at that list if things you want to know, you’ll find that you already know what columns you need. Taken in the order I listed them, you want one column for ‘Balance’, one for ‘Date’, one for each account such as ‘Checking’ and ‘CreditCard’, and one for ‘Notes’.

Those are your column headers. Enter one word per column as text in the first row. It doesn’t matter what order you do them in, as long as the order makes sense to you. I often put date first, then balance, but that’s just me.

Once you’ve labeled each column, give each one a name. I recommend the same names as the labels you gave them. That’s what I’ll be using.

Second row
The first row is now occupied by the column labels, so it’s time to look at the second row. Let’s say that you’re starting the budget by recording the paycheck you received on December 1st, and prior to December 1st the balance was zero.

  • In the “Date” column, enter December 1. You can use any format you want, as long as you’re either consistent in your formatting, or it recognizes it as a date. I’ll discuss date handling later.
  • In the ‘Balance’ column, enter the formula ‘=Checking + CreditCard’ (without the ‘’).
  • In the ‘Checking’ column, enter the amount of your paycheck. I’m going to arbitrarily say $1000. You don’t need to use the dollar sign.
  • In the ‘CreditCard’ column, enter 0, since your paycheck wasn’t deposited both places.
  • In the ‘Notes’ column, enter the text ‘Paycheck’.

Third row
Say you had to pay $500 rent on Dec 2nd. That should be entered in your third row.

  • In the “Date” column, enter December 2.
  • In the ‘Balance’ column, you’re doing something slightly different! If you just entered the formula ‘=Checking + CreditCard’, you wouldn’t actually be getting the balance, because the previous balance is no longer zero. Now, assuming that ‘Balance’ is in column B, the formula needs to be ‘=Checking + CreditCard + B2’. If you put the ‘Balance’ column in the first column, column A, then the formula would be +A2 instead of +B2.
  • In the ‘Checking’ column, enter the negative amount of your rent. I’m going to arbitrarily say $600, so enter -600.
  • In the ‘CreditCard’ column, enter 0, since you paid by check, not by credit card.
  • In the ‘Notes’ column, enter the text ‘Rent’.

The value in the ‘Balance’ column should now be $400. Is it $1600? You forgot to make your rent negative. Is it $-600? You didn’t add the previous balance. Is it $1000, you only added the previous balance, and didn’t add today’s transactions.

Row 4
One last example row… let’s say you went grocery shopping on December 2, paid with a credit card, and spent $50.

  • In the “Date” column, enter December 2.
  • In the ‘Balance’ column, copy the cell above, and paste it into this cell. Note that ‘B2’ in the formula automatically transforms into ‘B3’, so from now on all you need to do is copy this formula and paste it into the new row.
  • In the ‘Checking’ column, enter 0 — you paid with a credit card, not with a check.
  • In the ‘CreditCard’ column, enter -50.
  • In the ‘Notes’ column, enter the text ‘Groceries’.

The value in the ‘Balance’ column should now be $350.

Get the idea? Obviously this can get a lot more complex, but it’s always best to start small and work your way up.