Compare
Best Synastry Calculators Compared
This is our own site, so read it with that in mind. Prices come from public pages we read on November 6, 2026, and they may have changed.
The short answer
If you only want to see how two charts connect, you don’t need to pay anywhere on this list. They differ in how much they explain for free and in what they sell on top.
What each one gives you
Swipe the table to see more
| Site | Free | Paid |
|---|---|---|
| Synastry Calculator (this site, ours) | All planets, every aspect with a plain-English line, scores, house overlays, composite chart. No account. | One relationship report: $13.90, paid once. No subscription. |
| synastrychart.org | Inner-planet synastry, basic scores and summary interpretations. | Outer planets, longer interpretations, weekly briefings and monthly reports: $14.99 a month or $109 a year. Year Ahead report: $14.99. |
| theinnerwheel.com | A synastry calculator, with some readings locked. | Long PDF reports: $55; Chiron and Lilith reports: $39. |
| astrolibrary.org | Free tools. | Relationship report: $16. |
| nextastrology.com | A free synastry chart. | Full love calculator, dating calendar and other extras: from $9.99 a month or $99.99 a year. |
| astro-charts.com | Synastry chart and readings, mostly free. | Synastry guide: $35. |
We haven’t paid for any of these, so we can’t tell you how good their reports are.
How to choose
- You know both birth times: pick one that shows house overlays and rising signs for free.
- You don’t know their birth time: check that the site tells you what changes without it. Ours says so on the result.
- You’re new to astrology: look for plain-English lines on each aspect, not only a table of symbols.
- You want privacy: check whether birthdays end up in the page address when you share a link. Ours never puts them there.
Where ours falls short
Our site is new, and we have no subscription or weekly reports. We only cover Western tropical astrology, with no Vedic matching. Our scores use weights we designed ourselves, published on how we calculate, and other sites will give you different numbers.