Trust is earned, not assumed. We're transparent about how our calculations work, how they compare to established services, and why you might occasionally see small differences between astrology platforms.
Our Approach to Accuracy
Aurathea uses an independent calculation engine based on the Swiss Ephemeris—the same astronomical data source used by leading astrology software. We don't scrape or copy charts from other services. Every calculation is performed fresh using your exact birth data, ensuring consistency and traceability.
Cross-Verification with Established Services
We regularly cross-check our calculations against established services like Astro.com and Astro-Seek. For the same input data (date, time, location), planetary positions typically agree within 1 arc-minute—often less. This is well within the precision that matters for astrological interpretation.
Note: 1 arc-minute = 1/60th of a degree. The Sun moves about 1 degree per day, so 1 arc-minute represents roughly 1.4 minutes of time difference.
Why Small Differences Occur
Small differences between astrology services are normal and expected. Here's why they happen:
- House system implementations: At extreme latitudes (above 66°), some house systems behave differently. Services may handle these edge cases with different fallback rules.
- Aspect orbs: Different traditions use different orbs. We use traditional orbs (8° for major aspects), but some services use tighter or looser orbs.
- Display rounding: We calculate to high precision internally but round for display. A planet at 15°29'30" might show as 15°30' on one service and 15°29' on another.
- Mean vs. True Node: The lunar nodes can be calculated as mean (averaged) or true (actual). We use True Node by default, which shows slight oscillation.
Known Limitations
We believe in being upfront about our limitations:
- Extreme latitudes: For birthplaces above 66° latitude (Arctic/Antarctic), some house systems cannot produce meaningful results. We handle this gracefully, but results may differ from other services.
- Historical timezones: Timezone data before 1970 can be incomplete in some regions. For very old birth dates in areas with complex timezone histories, minor discrepancies may occur.
- City database coverage: While we cover 43,000+ cities, very small villages may not be in our database. You can always enter coordinates manually for precise locations.
How to Verify Our Results
We encourage you to verify our calculations. Here's how:
- Generate your chart on Aurathea with your exact birth data
- Generate the same chart on Astro.com or Astro-Seek using identical inputs
- Compare planetary positions—they should agree within 1 arc-minute
- Ensure you're using the same house system on both platforms
Our Commitment
If you find a calculation that seems incorrect, we want to know. We continuously verify and improve our algorithms. Accuracy is a journey, not a destination—and we're committed to that journey. Reach out through our contact page with your birth data and the discrepancy you've found, and we'll investigate.
See our methodology in detail
View Calculation Methodology