Is there a way to correct the speedometer for a change of tires? I went to a smaller diameter overall and am off about 5 percent.

 

One way to correct it is by getting a speedometer recalibration tool or tuner. These devices can adjust the speedometer settings to account for the new tire size so that it reads accurately.
Another option is talking to a mechanic or dealership. They may be able to reprogram your vehicle's computer to adjust for the new tire size.
If you're looking for a DIY solution, you can also calculate the difference in tire diameter between your old and new tires and adjust your speedometer readings accordingly. Using the ruler at https://ruler.onl/ could help you get those measurements faster.