Indicative WBSO calculator — 2026
For employers subject to Dutch payroll tax. The calculation is indicative; the RVO decision and available payroll tax remain decisive.
S&O wages:
Costs and expenditures:
S&O base:
BY PETER KLAREN · REVIEWED 19 SEPTEMBER 2026 · SOURCE: RVO WBSO GUIDE 2026
CALCULATE FOR
2026 final 2027 provisional Based on the announced WBSO parameters for 2027 and the Fiscale verzamelwet 2027. The percentages and bracket threshold remain unchanged; a fixed S&O hourly amount of €33 is proposed. Not yet final.
YOUR SITUATION
Employer / BV with employees Self-employed professional without staff Self-employed professional with employees
EMPLOYEE R&D HOURS
USED WBSO BEFORE?
No — fixed hourly amount Yes — own S&O hourly wage
S&O HOURLY WAGE
First WBSO application? Then €29 automatically applies in 2026 (provisionally €33 in 2027).
WBSO STARTER?
No Yes
ACTUAL COSTS AND EXPENDITURES
Enter the expected amount directly attributable to R&D for comparison.
EXPECTED ANNUAL PAYROLL TAX (OPTIONAL)
The payroll tax reduction cannot reduce the available payroll tax below zero.
COSTS AND EXPENDITURES — CHOOSE FOR THE MAIN CALCULATION
Fixed amount: €10/€4 per R&D hour Actual costs and expenditures
This hourly costs-and-expenditures allowance is separate from the fixed S&O hourly amount.
WBSO CALCULATION
S&O wages €87,000 Fixed amount/costs €22,800 S&O base €109,800
First bracket: 36% × €109,800 = €39,528
Second bracket: 16% × €0 = €0
THEORETICAL WBSO €39,528
Have my calculation reviewed
BASED ON THE PAYROLL TAX ENTERED, OFFSETTABLE €0
COMPARISON OF COST METHODS
With fixed amount €39,528 With actual costs €49,320 Difference €9,792
OWN R&D AS SELF-EMPLOYED PROFESSIONAL
AT LEAST 500 R&D HOURS?
Yes No
AT LEAST 1,225 BUSINESS HOURS?
Yes No
STARTING SELF-EMPLOYED PROFESSIONAL?
No Yes
Based on your entries, you meet both hour requirements S&O deduction €15,979 Additional starter deduction €0 Total deduction €15,979
Indicative calculation. The RVO decision, your actual payroll tax, approved hours and costs are decisive. No rights can be derived from the result.
How is WBSO calculated?
For employers, the S&O base consists of S&O wages plus an amount for costs and expenditures. In 2026, 36% applies to the first €391,020, or 50% for starters. The remainder is subject to 16%.
S&O wages = R&D hours × established S&O hourly wage
S&O base = S&O wages + hourly costs-and-expenditures allowance OR approved actual costs/expenditures
WBSO = percentage for first bracket + 16% over the remainder
Which S&O hourly wage do you use?
If RVO has historical S&O wage data, RVO establishes one average S&O hourly wage for the calendar year. If RVO cannot do so, for example for a first application, €29 automatically applies in 2026. For 2027, €33 has provisionally been announced.
This fixed hourly amount is different from the hourly costs-and-expenditures allowance. Read more about WBSO wage costs and the S&O hourly wage.
Fixed amount or actual costs and expenditures?
With the first application of the calendar year, you choose either the hourly costs-and-expenditures allowance or actual costs and expenditures. That choice applies to all applications in that year.
The hourly costs-and-expenditures allowance is €10 per R&D hour for the first 1,800 hours and €4 per hour above that. Actual costs and expenditures must be directly attributable and serviceable to your own R&D. The calculator compares both methods; a higher result is not a guarantee that all entered actual costs will be approved.
See which WBSO costs and expenditures qualify →
Three WBSO calculation examples
3,000 hours, first application
S&O wages: 3,000 × €29 = €87,000. Fixed cost amount: €22,800. Base: €109,800. WBSO: 36% = €39,528.
Starter, €200,000 base
The entire base falls within the first bracket. WBSO: 50% × €200,000 = €100,000.
€500,000 base
First bracket: 36% × €391,020 = €140,767. Second bracket: 16% × €108,980 = €17,437. Total approximately €158,204.
Calculating WBSO for self-employed professionals
Self-employed professionals do not receive a percentage over an S&O base. With at least 500 R&D hours and the tax hour criterion of 1,225 hours, the fixed S&O deduction in 2026 is €15,979. Starting self-employed professionals may receive an additional deduction of €7,996; total €23,975.
A self-employed professional with employees can use the fixed deduction for their own activities and the S&O payroll tax reduction for employees. The calculator therefore includes a separate combined situation.
Provisional WBSO calculation for 2027
According to the WBSO parameters announced around Budget Day, 36%, 50%, the €391,020 threshold and 16% remain unchanged. The Fiscale verzamelwet 2027 proposes increasing the fixed S&O hourly amount from €29 to €33. The changes are not yet final and remain subject to parliamentary approval. Definitive amounts for self-employed professionals for 2027 are therefore not yet calculated.
View all announced WBSO changes for 2027 →
Frequently asked questions about calculating WBSO
How do I calculate WBSO in 2026?
First calculate the S&O wages, add either the hourly costs-and-expenditures allowance or actual costs and expenditures, then apply 36% up to €391,020 and 16% to the remainder. For starters, 50% applies in the first bracket.
What is the difference between the fixed hourly amount and the hourly costs-and-expenditures allowance?
The fixed S&O hourly amount (€29 in 2026) determines S&O wages when no historical hourly wage is available. The hourly costs-and-expenditures allowance adds €10 and €4 respectively per R&D hour for costs and expenditures.
Can WBSO be higher than my payroll tax?
The theoretical calculation may be higher, but payroll tax payable cannot be reduced below zero. Amounts that cannot be offset are not automatically paid out.
What does a self-employed professional receive?
In 2026, a fixed S&O deduction of €15,979 and, for starters, potentially an additional €7,996, provided the hour requirements are met.
Are the 2027 figures final?
No. The 2027 selector uses the announced percentages and threshold and the proposed fixed S&O hourly amount of €33. Parliamentary approval is still required.
Have your WBSO calculation reviewed
Check the hours, hourly wage, cost choice and expected benefit before submission.
Schedule a technical intake
SOURCES AND SUBSTANTIVE REVIEW
RVO — WBSO Guide 2026
Reviewed by Peter Klaren, WBSO specialist since 2004. Last substantively updated: 21 September 2026.