Ovulation Calculator
Determine the exact biological fertility window, estimated ovulation day, and next expected menses based on cycle length and luteal phase variations.
Cycle Parameters
Clinical Precision & Methodology
The Ovulation Calculator uses luteal phase logic rather than simple halving. Since the luteal phase (post-ovulation) is biologically fixed at roughly 14 days for most women, ovulation is calculated backward from the next expected period.
Luteal Subtraction Method
Rather than dividing the cycle by two, ovulation is accurately determined by subtracting the luteal phase length (typically 14 days) from the total cycle length.
Biological Fertility Window
Automatically calculates the 6-day fertile window, accounting for sperm viability (up to 5 days) and ovum lifespan (12-24 hours post-ovulation).
Thermal Receipt Export
Generates a high-resolution, perfectly scaled PNG image designed specifically for 80mm thermal printers, enabling instant clinical handouts.