Why do i have pain & cramps in my calves?

Several reasons: It might be from poor conditioning and tight calf muscles. They need to be progressively stretched. It is unlikely to be a blood clot that occurs on both calves at the same time. Electrolyte imbalance with low or high potassium, magnesium, or calcium might be the problem. Are you on meds that might alter their levels? Even improper shoes, (heels especially), can contribute to this.