If you are using a CBD dropper or CBD Spray, not every drop or spray will be the same so you will have to roughly estimate dosages. Here is an infographic on measuring your tincture dosages:

CBD Capsules are usually pretty self explanatory as you can identify the dosage per capsule on the packaging. Regardless, the dosages are: for a 600mg bottle = 20mg per capsule, for a 1200mg bottle = 40 mg per capsule.