Pregnancy Calculators

What this category will cover

Pregnancy comes with a lot of dates and numbers to keep track of — due dates, ovulation windows, trimester milestones, and healthy weight gain ranges. Our goal here is the same as everywhere else on Trendy String: give you the number instantly, explain what it means in plain language, and leave the medical judgment calls to your doctor.

Which calculator should you use?

• Ovulation Calculator — find your most fertile days based on your average cycle length, useful if you're trying to conceive.
• Pregnancy Due Date Calculator — estimate your due date, current trimester, and conception date from your last menstrual period.
• Pregnancy Weight Gain Calculator — find a healthy total weight gain range based on your pre-pregnancy BMI.

A note on accuracy

These tools give educational estimates based on standard clinical formulas — not a diagnosis or a substitute for prenatal care. Always confirm dates and health decisions with your doctor or midwife.

Pair it with

Alongside these, our BMI Calculator in Fitness and Calorie & TDEE Calculator in Nutrition can help you track your starting point and daily energy needs.