Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Pregnancy
Gestational Age Calculator
Converts the number of days since your last menstrual period into gestational age expressed as weeks and days. Use it at any point in pregnancy to know your exact stage for prenatal care, screenings, and milestone tracking.
Fill in the required fields to see your result.
Pregnancy
Conception Date Calculator
Estimates the most likely conception date by counting back 266 days (38 weeks) from your due date. Useful when you know your due date but want to narrow down when fertilization likely occurred.
Fill in the required fields to see your result.
Key differences
| Gestational Age Calculator | Conception Date Calculator | |
|---|---|---|
| Category | Pregnancy | Pregnancy |
| Inputs required | 1 | 1 |
| Result | Gestational age (weeks) | Days since conception (days ago) |
| What it does | Converts the number of days since your last menstrual period into gestational age expressed as weeks and days. Use it at any point in pregnancy to know your exact stage for prenatal care, screenings, and milestone tracking. | Estimates the most likely conception date by counting back 266 days (38 weeks) from your due date. Useful when you know your due date but want to narrow down when fertilization likely occurred. |