Dog Pregnancy Calculator by MarkEnhanced Dog Pregnancy CalculatorEstimate your dog’s whelping date and track pregnancy stages. Mating Date ? Select the date of successful mating (e.g., 2025-04-01). Gestation Period (days) ? Average is 63 days; range is 58–68 days (e.g., small breeds: ~60, large breeds: ~65). Calculate ResetEnter the mating date, then click “Calculate”. JavaScript is disabled. Please enable it to use the calculator.