About Bump Calculator

Bump Calculator is a small, independent site with one job: give expecting and trying-to-conceive parents simple, trustworthy tools without the noise. No accounts, no tracking of your health data, no paywalls — every calculator runs entirely in your browser and your inputs never leave your device.

How our tools are built

Each calculator is based on published clinical guidance and widely used formulas — like Naegele's rule for due dates and standard luteal-phase math for ovulation — from sources such as the American College of Obstetricians and Gynecologists (ACOG), the UK's National Health Service (NHS) and peer-reviewed research. Every tool page lists its sources at the bottom, so you can check our work.

Who's behind it

Bump Calculator is built and maintained by 1UP Media AB, a small Swedish web publisher, and was created by a parent who spent too many late nights with a phone in one hand timing contractions with the other. We build the tools we wished we'd had.

What we are not

We are not doctors, and nothing on this site is medical advice. Our calculators produce estimates based on averages — your pregnancy is not an average. Always talk to your doctor or midwife about your results, and contact them right away about anything that worries you.

Contact

Questions, corrections or suggestions? We genuinely want them: hello@bumpcalculator.com