Analyze trends, coverlines, cycle phases, and temperature rises. See probable ovulation, fertile timing, and reminders. Plan charting confidently with examples, exports, guidance, and insights.
Enter daily waking temperatures taken before getting out of bed. Use the same method, time range, and thermometer whenever possible.
| Day | Example Temperature (°C) | Cycle Note |
|---|---|---|
| 1 | 36.42 | Period start |
| 2 | 36.39 | Low stable phase |
| 3 | 36.36 | Low stable phase |
| 4 | 36.40 | Low stable phase |
| 5 | 36.41 | Low stable phase |
| 6 | 36.38 | Low stable phase |
| 7 | 36.35 | Low stable phase |
| 8 | 36.44 | Possible transition day |
| 9 | 36.62 | First higher temperature |
| 10 | 36.67 | Sustained rise |
| 11 | 36.70 | Sustained rise |
| 12 | 36.71 | Luteal phase |
This calculator uses a practical chart-review approach. It checks for a sustained temperature rise after several lower temperatures.
Coverline = Highest temperature from previous comparison days + rise threshold Probable ovulation day = Day before the first of 3 temperatures above the coverline Fertile window = Ovulation day - 5 through ovulation day + 1 Temperature shift = Average of first 3 high temperatures - Average of previous comparison days Sustained high days = Consecutive days remaining above the coverline after the riseThe pregnancy-style pattern screen looks for temperatures staying elevated for many days after ovulation. That pattern can be helpful, but it is not proof of pregnancy.
After entering your readings, use the PDF download button to create a printable chart summary. You can also print the page directly from your browser if you want a paper chart for personal tracking or appointments.
Basal body temperature is your resting temperature taken immediately after waking and before activity. Small cycle-related hormone changes can shift it, especially after ovulation when progesterone usually causes a measurable rise.
No single absolute temperature confirms pregnancy. A more meaningful pattern is temperatures remaining elevated for about 18 or more days after ovulation. Confirm pregnancy with an appropriate test instead of relying on temperature alone.
Around ovulation, some people notice a slight dip, but the more reliable clue is a sustained rise afterward. The rise usually appears once progesterone increases following ovulation, not exactly at the moment ovulation happens.
A non-pregnant chart often shows temperatures dropping before menstruation. A chart associated with pregnancy may remain elevated beyond the expected period. Still, charts can vary, so use tests and clinical guidance for confirmation.
A sustained rise usually signals that ovulation likely already occurred and progesterone increased. It is more useful for confirming the post-ovulation phase than for predicting ovulation in advance during the same cycle.
If conception happens, temperatures may stay elevated instead of dropping before a period. That pattern can be encouraging, but it is not definitive. A home pregnancy test or clinician-guided testing provides confirmation.
More data is usually better. At minimum, you need several lower temperatures followed by at least three higher temperatures. Consistent timing and fewer disturbances improve the reliability of any chart interpretation.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.