Fringe is the line that turns a salary into what an employee actually costs you. It is not a markup and it is not negotiable folklore: it is a rate you calculate from your own payroll records, apply consistently to every project, and can defend three years later.
What fringe covers
The pool is everything you pay on top of wages because someone is an employee. In a small company that usually means the employer share of payroll taxes, unemployment insurance, workers compensation, health and dental premiums you contribute to, any retirement contribution or match, disability and life coverage, and paid time off where your policy accrues it rather than charging it as worked hours.
What does not belong in the pool is anything you already recover somewhere else. Office rent, software licenses, and administrative support are overhead and belong in your indirect pool, which is a separate calculation with a separate base. The boundary between the two pools is exactly where fringe errors start. Contractor and consultant payments carry no fringe at all, because those people are not on your payroll.
Computing a rate you can defend
The arithmetic is simple. Add up the fringe pool for a defined period, usually your last complete fiscal year, divide it by the total salaries and wages paid in the same period, and express the result as a percentage. Apply that percentage to the salary dollars charged to the project.
Two rules make it defensible. Use the same period for the numerator and denominator, and apply one rate across all employees unless you deliberately maintain separate pools for genuinely different groups. Keep the worksheet. When a grants specialist or an auditor asks how you arrived at your number, a one-page calculation tied to payroll reports ends the conversation.
A young company with almost no benefits lands at a low rate driven mostly by payroll taxes; one with real health coverage and a retirement match lands considerably higher. Both are fine. What is not fine is borrowing a rate from a university or a sample budget, because that number describes someone else's payroll.
Founder salaries and the audit risk
Founders are usually employees for this purpose, and their salary and fringe are charged like anyone else's — based on actual compensation, reasonable for the role and the region, and supported by timekeeping that records effort on the project. How you can be paid at all depends on how the business is organized, which is one more reason the choice between an LLC and a sole proprietorship matters before you apply. You cannot charge a founder salary you are not actually paying, and you cannot commit more effort across all your awards and your other work than the hours in a week. That last check is one an agency really does perform.
An invented rate is not a rounding error. It is a finding, and findings on a federal award can mean disallowed costs and repayment long after the money is spent. The payroll records behind your rate are the same ones that back up your post-award reporting. How award money is treated on your books, including whether SBIR funds are taxable income, belong to the same conversation with your accountant, and inconsistent labor numbers show up on every list of budget mistakes that sink applications.
This is general information, not accounting or tax advice — have your CPA compute and sign off on your fringe rate.
Projects House defines the engineering tasks and hours a federal budget is built from. Reach us through the contact form.