v3.26.1
Shareholder Report
6 Months Ended
Jun. 30, 2026
USD ($)
Holdings
Shareholder Report [Line Items]  
Document Type N-CSRS
Amendment Flag false
Registrant Name ROYCE CAPITAL FUND
Entity Central Index Key 0001006387
Entity Investment Company Type N-1A
Document Period End Date Jun. 30, 2026
Shareholder Report Annual or Semi-Annual Semi Annual Shareholder Report
Royce Capital Fund - Micro-Cap Portfolio - Investment Class  
Shareholder Report [Line Items]  
Fund Name Royce Capital Fund—Micro-Cap Portfolio
Class Name Investment Class
Trading Symbol RCMCX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about Royce Capital Fund—Micro-Cap Portfolio for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual Semi Annual Shareholder Report
Additional Information [Text Block] You can find additional information at www.royceinvest.com/literature. You can also request this information by contacting us at 1-800-221-4268.
Additional Information Phone Number 1-800-221-4268
Additional Information Website www.royceinvest.com/literature
Expenses [Text Block]

What Were the Fund’s Costs for the Last Six-Months?

Based on a hypothetical $10,000 investment

 

FUND/CLASS

COSTS OF A

$10,000 INVESTMENT

COSTS PAID AS A PERCENTAGE
OF A $10,000 INVESTMENT¹
Royce Capital Fund—Micro-Cap Portfolio—Investment Class $74 1.22%
¹Annualized    

 

Expenses Paid, Amount $ 74
Expense Ratio, Percent 1.22% [1]
Net Assets $ 141,000,000
Holdings Count | Holdings 156
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

As of/through 6/30/26

 

Fund Size (Millions) $141
Number of Holdings 156
Portfolio Turnover Rate 22%

Holdings [Text Block]
 

Portfolio Sector Breakdown

 

Portfolio Sector Breakdown  
Industrials
Information Technology
Health Care
Consumer Discretionary
Financials
Materials
Energy
Communication Services
Real Estate
Cash and Cash Equivalents

 

Largest Holdings [Text Block]

 

Top 10 Positions  
Ultra Clean Holdings 1.7  
Ichor Holdings 1.7  
Graham Corporation   1.5  
NWPX Infrastructure   1.5  
Cohu   1.4  
Lincoln Educational Services   1.4  
Bel Fuse Cl. B   1.4  
EZCORP Cl. A   1.3  
Lindblad Expeditions Holdings 1.3  
Digi International 1.2  
Updated Prospectus Phone Number 1-800-221-4268
Updated Prospectus Web Address www.royceinvest.com
Royce Capital Fund - Micro-Cap Portfolio - Service Class  
Shareholder Report [Line Items]  
Fund Name Royce Capital Fund—Micro-Cap Portfolio
Class Name Service Class
Trading Symbol RCMSX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about Royce Capital Fund—Micro-Cap Portfolio for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual Semi Annual Shareholder Report
Additional Information [Text Block] You can find additional information at www.royceinvest.com/literature. You can also request this information by contacting us at 1-800-221-4268.
Additional Information Phone Number 1-800-221-4268
Additional Information Website www.royceinvest.com/literature
Expenses [Text Block]

What Were the Fund’s Costs for the Last Six-Months?

Based on a hypothetical $10,000 investment

 

FUND/CLASS

COSTS OF A

$10,000 INVESTMENT

COSTS PAID AS A PERCENTAGE OF A $10,000 INVESTMENT¹
Royce Capital Fund—Micro-Cap Portfolio—Service Class $90 1.49%
¹Annualized    

 

Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher. 

Expenses Paid, Amount $ 90
Expense Ratio, Percent 1.49% [2]
Net Assets $ 141,000,000
Holdings Count | Holdings 156
Investment Company, Portfolio Turnover 22.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics

As of/through 6/30/26

 

Fund Size (Millions) $141
Number of Holdings 156
Portfolio Turnover Rate 22%

Holdings [Text Block]
 

Portfolio Sector Breakdown

 

Portfolio Sector Breakdown  
Industrials
Information Technology
Health Care
Consumer Discretionary
Financials
Materials
Energy
Communication Services
Real Estate
Cash and Cash Equivalents

 

Largest Holdings [Text Block]

 

Top 10 Positions  
Ultra Clean Holdings 1.7  
Ichor Holdings 1.7  
Graham Corporation   1.5  
NWPX Infrastructure   1.5  
Cohu   1.4  
Lincoln Educational Services   1.4  
Bel Fuse Cl. B   1.4  
EZCORP Cl. A   1.3  
Lindblad Expeditions Holdings 1.3  
Digi International 1.2  
Updated Prospectus Phone Number 1-800-221-4268
Updated Prospectus Web Address www.royceinvest.com
Royce Capital Fund-Small-Cap Portfolio - Investment Class  
Shareholder Report [Line Items]  
Fund Name Royce Capital Fund—Small-Cap Portfolio
Class Name Investment Class
Trading Symbol RCPFX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about Royce Capital Fund—Small-Cap Portfolio for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual Semi Annual Shareholder Report
Additional Information [Text Block] You can find additional information at www.royceinvest.com/literature. You can also request this information by contacting us at 1-800-221-4268.
Additional Information Phone Number 1-800-221-4268
Additional Information Website www.royceinvest.com/literature
Expenses [Text Block]

What Were the Fund’s Costs for the Last Six-Months?

Based on a hypothetical $10,000 investment 

  COSTS OF A COSTS PAID AS A PERCENTAGE
FUND/CLASS $10,000 INVESTMENT OF A $10,000 INVESTMENT1
Royce Capital Fund—Small-Cap Portfolio—Investment Class $67 1.23%
1Annualized    

 

Expenses Paid, Amount $ 67
Expense Ratio, Percent 1.23% [3]
Net Assets $ 187,000,000
Holdings Count | Holdings 79
Investment Company, Portfolio Turnover 24.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics  

As of/through 6/30/26 

 

Fund Size (Millions) $187
Number of Holdings 79
Portfolio Turnover Rate 24%
Holdings [Text Block]
 

Portfolio Sector Breakdown 

 

Portfolio Sector Breakdown  
Financials
Consumer Discretionary
Industrials
Information Technology
Health Care
Energy
Consumer Staples
Cash and Cash Equivalents

Largest Holdings [Text Block]

 

 
Top 10 Positions    
TD SYNNEX 2.7  
M/I Homes 2.4  
Blue Bird 2.3  
Diebold Nixdorf 2.2  
Timberland Bancorp 2.0  
Village Super Market Cl. A 2.0  
IBEX 2.0  
Interface 2.0  
PulteGroup 2.0  
Unity Bancorp 1.8  
Updated Prospectus Phone Number 1-800-221-4268
Updated Prospectus Web Address www.royceinvest.com
Royce Capital Fund-Small-Cap Portfolio - Service Class  
Shareholder Report [Line Items]  
Fund Name Royce Capital Fund—Small-Cap Portfolio
Class Name Service Class
Trading Symbol RCSSX
Annual or Semi-Annual Statement [Text Block] This semiannual shareholder report contains important information about Royce Capital Fund—Small-Cap Portfolio for the period of January 1, 2026 to June 30, 2026.
Shareholder Report Annual or Semi-Annual Semi Annual Shareholder Report
Additional Information [Text Block] You can find additional information at www.royceinvest.com/literature. You can also request this information by contacting us at 1-800-221-4268.
Additional Information Phone Number 1-800-221-4268
Additional Information Website www.royceinvest.com/literature
Expenses [Text Block]

What Were the Fund’s Costs for the Last Six-Months?

Based on a hypothetical $10,000 investment 

  COSTS OF A COSTS PAID AS A PERCENTAGE
FUND/CLASS $10,000 INVESTMENT OF A $10,000 INVESTMENT1
Royce Capital Fund—Small-Cap Portfolio—Service Class $78 1.42%
1Annualized    

 

Reflects fee waivers and/or expense reimbursements, without which expenses would have been higher.

Expenses Paid, Amount $ 78
Expense Ratio, Percent 1.42% [4]
Net Assets $ 187,000,000
Holdings Count | Holdings 79
Investment Company, Portfolio Turnover 24.00%
Additional Fund Statistics [Text Block]

Key Fund Statistics  

As of/through 6/30/26. 

 

Fund Size (Millions) $187
Number of Holdings 79
Portfolio Turnover Rate 24%
Holdings [Text Block]
 

Portfolio Sector Breakdown 

 

Portfolio Sector Breakdown  
Financials
Consumer Discretionary
Industrials
Information Technology
Health Care
Energy
Consumer Staples
Cash and Cash Equivalents

Largest Holdings [Text Block]

 

 
Top 10 Positions    
TD SYNNEX 2.7  
M/I Homes 2.4  
Blue Bird 2.3  
Diebold Nixdorf 2.2  
Timberland Bancorp 2.0  
Village Super Market Cl. A 2.0  
IBEX 2.0  
Interface 2.0  
PulteGroup 2.0  
Unity Bancorp 1.8  
Updated Prospectus Phone Number 1-800-221-4268
Updated Prospectus Web Address www.royceinvest.com
[1] Annualized
[2] Annualized
[3] Annualized
[4] Annualized