I find Google Docs pretty useful, there are couple of templates for budgeting, check here https://docs.google.com/spreadsheets

I am a really big fan of mint.com!

I don't use budget tools and never have. Instead, I just worked up a simple spread sheet listing my financial obligations for the month that covers a 6 month period. Let's say it's the month of March and I know the sum total of my income for that month and likewise, I know the sum total of my financial obligations for the month. I've also set up all of my utilities on averaging so for a year my utility bills never change from one month till the next. I've also set up my checking account so that nearly all of my bills are auto-paid. That means all I have to do is pull up my checking account on the internet and check off each obligation as it hits my bank. Presto, no writing checks, no dropping off local utility payments, no late fees and no bank charges. I also know pretty closely what my food and entertainment costs and contributions will be so I know from one month to the next how much money I'll have left over to run on. It's sure nice to not have to spend a lot of time paying bills and knowing that they'll be paid before they're due.

I second You Need a Budget. Have been using it for 15 years and it makes a huge difference in attaining my financial goals.

Google Docs has a spreadsheet that may be accessed online. Very similar to excel or other spreadsheets. https://www.google.com/sheets/about/

I belong to a credit union and they have an online budgeting tool that works with my account which makes it easy to use and very secure. You should check to see if your bank has a budgeting tool before using a third party tool.

I second/third all the people recommending mint. I absolutely love it (I use the free version). It really lets you see where you are actually spending your money. The only kind of not good thing is that you have to link all your accounts to it which is a bit of a security risk. I also use google sheets for the daily managing of my credit card Hope this helps!

Excel. Hard to avoid the need to use excel anyhow, so might as well use it for budgeting too. That is, unless you have a specific specialized need or accounting rules.

I'm a fan of https://www.youneedabudget.com/!

You can get budget templates for Excel and use them. If you are looking to build and manage a budget for your business, then I would recommend using an accounting software that can track your income and expenses. Which in turn can be used to create a budget. I work with clients on budgets so let me know if I can help you with anything or if you have questions about how budgets work.