The Number Your Payslip Doesn’t Show You
You accepted a part-time role at what sounded like a fair salary. But do you actually know what that job pays at full-time hours? A lot of people don’t — and that gap in knowledge costs them when they’re negotiating, comparing offers, or tracking their career progress over time.
Your pro rata salary is the adjusted pay you receive for the hours you work. It’s not the same as what the role is worth at full capacity. Once you calculate full time salary from pro rata, you get the real number — the FTE (full-time equivalent) — and suddenly the comparison becomes clear.
This calculator does that math for you instantly. Enter your pro rata pay, your actual hours, and the standard full-time hours for the role. That’s it.
How the Calculation Works — And Why It Matters More Than You Think
The formula itself isn’t complicated, but the implications can surprise people.
Steps to Get Your Full-Time Equivalent Salary
- Enter your current pro rata (part-time) salary in the salary field.
- Select the period — annual, monthly, weekly, daily, or hourly.
- Enter the number of hours you actually work per week.
- Enter the standard full-time hours for this role (commonly 35, 37.5, or 40 hours).
- Choose your currency if needed.
- Hit Calculate. Your full-time equivalent salary appears immediately, broken down by year, month, week, day, and hour.
The Formula Behind the Result
The calculator uses one clean, universally accepted method:
Breaking Down the Formula
Full-Time Equivalent Salary = (Pro Rata Salary ÷ Actual Hours) × Full-Time Hours
Or expressed as a ratio: FTE Salary = Pro Rata Salary × (Full-Time Hours ÷ Your Hours)
This approach assumes pay scales linearly with hours — which is the standard assumption in employment, supported by guidance from bodies like the U.S. Department of Labor and equivalent agencies in other countries.
A Worked Example with Real Numbers
Say you earn $28,800 per year working 24 hours a week, and the full-time equivalent for the role is 40 hours. Divide $28,800 by 24 to get $1,200 per hour-week unit. Multiply by 40. Full-time equivalent: $48,000 per year. That’s the number you’d earn — and the number the employer has budgeted — for the role done full time.
Where This Number Actually Changes Things
Most people only think about their pro rata pay at the point of signing a contract. That’s a mistake. There are several situations where knowing your FTE salary is just as important.
Job Comparisons That Aren’t Actually Fair
If you’re comparing your current $32,000 part-time role against a $38,000 full-time offer elsewhere, you’re not comparing the same thing. You need to convert both to a common basis — usually FTE annual salary — before the comparison means anything.
When Benefits and Leave Are Tied to FTE
Some employers calculate pension contributions, bonus eligibility, and paid leave allowances based on FTE salary rather than pro rata salary. If you don’t know your FTE figure, you may not be able to verify whether those calculations are correct.
Three Things That Throw Off Your Calculation
Using the Wrong Full-Time Hours Baseline
Full-time isn’t universally 40 hours. In the UK, it’s often 37.5. In some sectors it’s 35. In others, it’s higher. Always check the contract or job description for the standard full-time hours — don’t assume. Using the wrong baseline will give you a FTE figure that’s off by a meaningful margin.
Mixing Up Salary Period and Pay Frequency
If you’re paid monthly but thinking in weekly figures, or vice versa, you’ll feed the calculator the wrong input. Double-check whether the number you have is annual, monthly, or something else before entering it. Most people know their monthly take-home but need to convert that to gross annual first — and those are not the same number.
Forgetting That Overtime Can Skew the Picture
If you regularly work more hours than your contract states — and many part-time workers do — your effective hourly rate may be lower than the calculation suggests. The calculator uses your contracted or stated hours. It can’t account for unpaid extra time. Most people skip this check and end up with an FTE figure that flatters the employer slightly.
Real Questions People Ask Before Running the Numbers
Is pro rata the same as part-time salary?
Yes. Pro rata salary is simply the portion of a full-time salary that corresponds to the hours you work. If a full-time role pays $50,000 and you work half the hours, your pro rata salary is $25,000.
What does FTE salary mean?
FTE stands for full-time equivalent. It’s the salary you would earn if you worked the standard full-time hours for that role. It’s a useful figure for comparisons and benchmarking.
How do I calculate annual salary from pro rata if I’m paid monthly?
Multiply your gross monthly pro rata pay by 12 to get your annual pro rata. Then apply the FTE formula: divide by your actual hours, multiply by full-time hours. The calculator handles all of this automatically if you select “monthly” as your salary period.
Can I use this to calculate actual salary from pro rata on a different hours contract?
Yes. If you’re moving from 24 hours to 30 hours within the same role, enter your current salary, current hours, and new hours as the full-time figure. The result shows your new equivalent — though your employer will confirm the actual offer.
Is the calculation different in the UK?
The formula is the same. The difference is that UK full-time hours are often 37.5 rather than 40. Make sure you enter the correct full-time hours baseline for your specific role. The UK government guidance on part-time worker rights confirms that pro rata calculations apply proportionally to hours worked.
Does this calculator work for hourly rate jobs?
Yes. Select “hourly rate” as the salary period, enter your hourly pay, your actual weekly hours, and the full-time hours. The calculator converts everything to an annual FTE and shows the hourly rate breakdown too.
What if my hours change week to week?
Use your average contracted weekly hours, not an unusually high or low week. If your contract doesn’t specify fixed hours, use the average over the last 12 weeks — that’s the standard method used for most employment calculations.
Should I use gross or net salary?
Always use gross salary — the amount before tax and deductions. FTE comparisons are always made on a gross basis because net pay varies by personal tax situation, which is irrelevant to what the role actually pays.
Once You Have the Number, Here’s What to Do With It
Write it down somewhere you’ll actually see it. If you’re due a salary review, you now have the exact FTE figure to reference when making a case for where your pay should be. If you’re comparing jobs, you can finally put two offers side by side on equal footing. And if something doesn’t add up — if your pro rata looks lower than it should relative to the FTE — that’s worth a direct conversation with HR.