The Kentucky Derby has a maximum field size of 20 horses, a limit that has been in place since 1975. However, the actual number of starters can vary due to scratches before the race. For example, in 2020, the field was smaller with only 15 horses competing due to several scratches

. For the 2025 Kentucky Derby, there are 20 post positions available, but the field is set to feature 19 horses following multiple scratches

. This shows that while the race can accommodate up to 20 horses, the final number may be slightly less depending on last-minute changes. In summary:

• Maximum horses allowed: 20
• Typical field size: Usually close to 20, but can be fewer due to scratches
• 2025 Kentucky Derby field: 19 horses competing after scratches