MotoAmerica has released the race distances for each class at each event on its 2019 schedule:
Superbike:
Circuit of The Americas, 15 laps (TBC), 51.45 miles
Road Atlanta, 21 laps, 53.55 miles
VIRginia International Raceway, 23 laps, 51.75 miles
Road America, 13 laps, 52.65 miles
Utah Motorsports Campus, 23 laps, 50.60 miles
WeatherTech Raceway Laguna Seca, 23 laps, 50.92 miles
Sonoma Raceway, 22 laps, 51.04 miles
Pittsburgh International Race Complex, 18 laps, 50.04 miles
New Jersey Motorsports Park, 23 laps, 51.75 miles
Barber Motorsports Park, 21 laps, 49.98 miles
TBC=To Be Confirmed
Supersport:
Road Atlanta, 18 laps, 45.90 miles
VIRginia International Raceway, 19 laps, 42.75 miles
Road America, 11 laps, 44.55 miles
Utah Motorsports Campus, 29 laps, 41.80 miles
WeatherTech Raceway Laguna Seca, 19 laps, 42.07 miles
Sonoma Raceway, 18 laps, 41.76 miles
Pittsburgh International Race Complex, 16 laps, 44.48 miles
New Jersey Motorsports Park, 20 laps, 45.00 miles
Barber Motorsports Park, 19 laps, 45.22 miles
Junior Cup:
Road Atlanta, 11 laps, 28.05 miles
VIRginia International Raceway, 12 laps, 27.00 miles
Road America, 7 laps, 28.35 miles
Utah Motorsports Campus, 12 laps, 26.40 miles
WeatherTech Raceway Laguna Seca, 12 laps, 26.57 miles
Sonoma Raceway, 12 laps, 27.84 miles
Pittsburgh International Race Complex, 10 laps, 27.80 miles
New Jersey Motorsports Park, 13 laps, 29.25 miles
Barber Motorsports Park, 11 laps, 26.18 miles
Stock 1000:
Road Atlanta, 13 laps, 33.15 miles
VIRginia International Raceway, 14 laps, 31.50 miles
Road America, 8 laps, 32.40 miles
Utah Motorsports Campus, 14 laps, 30.80 miles
WeatherTech Raceway Laguna Seca, 12 laps, 26.57 miles
Sonoma Raceway, 14 laps, 32.48 miles
Pittsburgh International Race Complex, 12 laps, 33.36 miles
New Jersey Motorsports Park, 15 laps, 33.75 miles
Barber Motorsports Park, 13 laps, 30.94 miles
Twins Cup:
Road Atlanta, 12 laps, 30.60 miles
VIRginia International Raceway, 13 laps, 29.25 miles
Road America, 8 laps, 32.40 miles
Utah Motorsports Campus, 13 laps, 28.60 miles
WeatherTech Raceway Laguna Seca, 12 laps, 26.57 miles
Sonoma Raceway, 13 laps, 30.16 miles
Pittsburgh International Race Complex, 11 laps, 30.58 miles
New Jersey Motorsports Park, 14 laps, 31.50 miles
Barber Motorsports Park, 12 laps, 28.56 miles