Whether you’re already established or just getting started with your business plan (and all the aggravation and time constraints that goes along with the process) expenses will always be mounting for your business, day after day, month after month, year after year.

Prior to the last decade, starting a business would require you to buy tons of books, hire the services of accountants and business startup experts, and generally run yourself ragged trying to predict and calculate all the startup costs involved in your business before going to your loan manager or private investor.

Other major costs that you’ll need to know before and after starting a business include marketing and other investment-related costs – and the resultant ROI they generate, along with the true cost of your employees and other overhead expenses.

Then there’s the be-all, end-all of all calculations: cash flow! If it isn’t flowing in you’re dead in the water. If payables aren’t being paid on time then bye-bye electricity, water, office spaces, building leases and vendors!

The following five small business calculators are a must for starting and running a successful SMB. Established business owners won’t require the Startup Cost Calculator and may never need to use the Loan Calculator, but you can certainly benefit from the final three that are mentioned.

1. Startup Cost Calculator

http://www.wsj.com/public/page/news-small-business-startupCalculator.html

A startup cost calculator is essential for determining just how much money it’s going to cost you to get your business up and running, and to keep it running while waiting for sales to start trickling in. You can’t formulate a business plan to take to the bank and/or investors without an accurate picture of all the costs associated with getting the doors open.

The WSJ Startup calculator shown above is free and among the most comprehensive in the industry. It allows you to quickly and easily plug in your startup expenses and assets, along with all the recurring overhead costs that you’ll contend with once you launch.

The calculator runs you through a 4-step process where you enter all your asset and expense data, then outputs your total startup costs, equity and expenses to give you a rough total of how much money you’ll need to make it all happen.

2. Small Business Loan Calculator

http://www.shopify.com/tools/business-loan-calculator

Once you have an idea as to what your business is going to cost you to run, it’s time to head out to the bank or a private lending company to find a loan – preferably a low interest, fixed rate loan that you can pay off in as short a time as possible!

It isn’t hard to shop around and look for the best interest rate and repayment terms once you’re ready to pull the trigger. However, when you’re still in the planning phase, it helps to be able to plug your desired loan amount and a few different common small business loan interest rates into a calculator to get a rough idea of what to expect when you visit the bank or lender. This simple calculator from Shopify shows you what your monthly payments will be and how much you can expect to pay in interest over the course of your repayment schedule.

3. Employee Cost Calculator

https://www.staff.com/true-cost-of-employees

This staff.com calculator is perfect for showing you not just how much you can afford to pay and employee, but how much they actually cost your business when it’s all said and done.

Employees cost your business more than their hourly wage or yearly salary. There’s recruitment costs to consider, benefits to account for, and the equipment and office supplies they’ll use to consider. Not to mention how much it costs you when they go on vacation, take a sick leave, or don’t work their scheduled work days.

Without this data, there’s no way to determine how much money you can afford to pay in salary. Nor can you decide on the various perks you can offer to attract the best staff in the industry, such as vacation time (above and beyond that which is mandated by your state or provincial laws), or bonus packages for going above and beyond your expectations.

4. Cash Flow Calculator

http://www.bankrate.com/brm/news/biz/green/19991129a.asp

Cash is king baby! Whether you’re running a service business or manufacturing a product(s), you need to have a clear picture of the true cost of doing business. Sales (minus) Expenses = Profits. Without these numbers it’s impossible to price out your products and services to meet your overhead cost demands, determine how much inventory you can afford to house, or decide what’s the ideal time to grow and expand the business.

There aren’t really any good automated cash flow calculators to be found online, but the link above from bankrate.com shows you the basic calculations required to keep tabs on your business’s cash flow and prevent hiccups. Most businesses are profitable when they go under. It’s the outstanding bills and receivables that often lead to bankruptcy for the majority of successful SMB’s.

5. Email and Direct Mail Marketing ROI Calculator

http://www.marketingtoday.com/tools/roi_calculator.htm

Last but not least, this marketing calculator from marketing today is perfect for businesses who invest a significant amount of startup capital and profits into marketing their business via direct mail and email marketing.

The calculator allots for both pre-planning projections and the actual results of each campaign after they’ve finished their run. Input your total mail pieces or emails, cost to send, response rate, conversions and average profit from each to get your total ROI from various campaigns.

So many businesses waste tons of cash on direct mail campaigns that don’t make them any money. Email marketing can be just as fickle, with the cost to put the campaigns together, and then also to maintain a reputable service to manage your lists for CAN-SPAM compliance.

Word of Caution

Keep in mind that the numbers you end up with after using any online calculator or accounting formula will only be as accurate as those you input to them. Do your financial legwork very carefully and make sure all your numbers are as solid as possible before relying on any calculations. Finally, it’s always advisable to go over the results with an accountant or money manager before going to the bank and/or actually launching the business.