A mathematical model has been created to examine the relationship between diet and exercise with respect to weight loss; Quantification of the effect of energy imbalance on bodyweight.
The NIH has provided a web based tool based on this work to help you plan a diet to lose weight, the body weight planner.
Note that 60-80% of calories consumed is used by the basal metabolic rate, digestion 10% and exercise only accounts for about 10% - 30% which explains why it is so hard to lose weight through exercise. Furthermore, people compensate for exercise by eating more, or relaxing after the exercise which reduces any weight loss benefit from the added exercise.
https://www.vox.com/2018/1/3/16845438/exercise-weight-loss-myth-burn-calories