Calories burned with strength training

Its difficult to work out how many calories you burn during strength training since it depends on sets, reps, weight and intensity. Best result you'll get is logging calories with a heart rate monitor. If you don't have one and don't want to get one, then you'll have to guesstimate like sijomial suggested.

Otherwise you can work out your BMR using an online calculator (or use the formula which should also be somewhere on the internet), correct for your activity level in terms of your exercise routine and intensity to get your required maintenance calories. Since there is an error involved in the calculation, the best place to start would be eat the calculated maintenance calories and see what your weight does in the next 2 weeks. If your goal is gaining weight (and I'm assuming it is since you posted in the weight gain section) and your weight stayed the same, add on another 100 calories and see what happens. Repeat until you get to the level of weight gain you are looking for to achieve the goal weight you set out. Its harder to put on muscle than fat, so I'd keep the calorie surplus relatively low and make it up with mostly protein to try and keep the muscle gains at a maximum and fat at a minimum. I'm not a fan of cycling between bulking and cutting. If you're gaining slow and steady and ensure mostly muscle gains, then you eliminate the need for a cutting cycle. Fair enough, its going to take a bit longer to gain the weight... but it should be a lot less counterproductive than cycling between gaining and losing...