how many calories is 18- 23 points

In general a point can be as low as 25 cal or as high as 75 depending on fat and fiber:

Point Range (123 Success Points) Converted to Calories
(This isn't always 100% true because of fiber)

18-25 points = 1050-1400 calories
20-27 points = 1150-1500 calories
22-29 points = 1250-1600 calories
24-31 points = 1350-1700 calories
26-33 points = 1450-1800 calories
28-35 points = 1550-1900 calories