Astrolium's Lots module is a workspace for Arabic Parts and Hermetic Lots. It casts each lot by sect, shows the formula it used, names the lot's ruler and plots the core set on a ring around the chart. When a formula has an alternative the engine cannot compute, the page says so in plain words. Lots is part of the $11 per month Pro plan; see pricing.
For a single lot without an account, the free Part of Fortune calculator and Lot of Spirit calculator run in the browser. For the doctrine, read the Arabic Parts guide.
What the Lots module calculates
A lot is a derived point. It has no body in the sky, only a distance between two things that do, carried over to start from the Ascendant. The Lot of Fortune measures the arc from Sun to Moon by day; the Lot of Spirit measures it the other way. Most of the Hermetic set is then cast from those two.
That dependency is why the module is careful about sect.
Sect, stated on screen
The header reads the natal sect and shows it. On a day chart, Fortune is Asc + Moon − Sun. On a night chart the two significators trade places and Fortune becomes Asc + Sun − Moon. Rows whose formula changes with sect carry a small sect badge, meaning the right branch was applied for this chart.
Hellenistic practice is not unanimous on this. The Settings page has a Day / Night Formula Reversal control with two options: by sect, or never reverse, which is Ptolemy's reading. Pick one and it applies to Fortune, Spirit and every lot built on them.
In the natal chart, the Arabic Lots panel adds one more flag. When the Sun sits close to the horizon, a Borderline note warns that the sect call is a near one, which matters because the whole reversal hangs on it.
Formulas you can read
Each row shows how the lot was cast: Asc + Venus − Saturn, or Asc + 19°Ari − Sun for the Lot of Honor. The chips come from the operands the calculation service returns for that exact chart, day or night. Terms such as 7th cusp or ruler of the 7th arrive as one chip each.
Two lots carry a formula note, because the engine applies one form and cannot compute the other.
The Lot of Marriage is cast in its masculine form, Asc + Venus − Saturn, on every chart. Dorotheus assigns the Venus/Saturn arc the other way round for women, so for a female native the number is not the Dorothean lot. Astrolium does not ask for a client's gender and does not pretend to correct for it.
The Lot of Honor is cast as Bonatti's unreversed form, Asc + 19°Ari − Sun, on every chart. By night the related Lot of Exaltation uses Asc + 3°Tau − Moon, and on a night chart the two can land far apart.
In the table the note is an info icon. In the detail panel it is always visible, because a practitioner studying one lot is the person who needs it.
The lot ring
Beside the table sits a compact wheel with the lots plotted on their own ring. The ten core lots, the seven Hermetic and three Relational, always appear there.
Lots can crowd. Fortune and Spirit are mirror images across the Ascendant, so they coincide near a New or Full Moon and stand opposed at the quarters, and Eros and Necessity can join the pile. The ring handles this with two thresholds. Lots within about 3° of one another are treated as the same point and share a marker. Lots further apart that would still overlap on screen are fanned out along the ring, and each one keeps its own leader line back to its true degree, so a spread never reads as a conjunction.
Custom lots join the ring up to four at a time; the one you have selected always gets a place. The table below the ring lists every lot, custom or built-in.
Build your own lot
The builder writes formulas in the same point language as the built-in lots: a from point, a point to add, a point to subtract. The points are the Ascendant, the Midheaven, Fortune, Spirit and the seven classical planets. A checkbox reverses plus and minus by sect, day to night.
Name the lot and save it. The formula stays in the builder if a save fails, so nothing is retyped. Saved lots sync to your account and appear under Custom lots, with a delete control on each.
Built-in lots come from the verified calculation service. If that service does not return a complete calculation, the module shows an error and a retry button rather than a locally computed stand-in.
Where lots show up elsewhere
- In the natal chart, the Arabic Lots panel lists lots with longitude, sign and house, lets you pin any lot to the wheel, and shows lots conjunct natal planets with their orb. See the natal chart workspace.
- On the Datasheet, a Hermetic lots strip carries the core lots with house and formula, and links to the full catalogue and builder.
- Each lot has an Ask AI button to interpret it. The assistant receives the natal chart, the Fortune and Spirit positions and the resolved sect.
- Report Studio has an Arabic lots block for Fortune, Spirit, Eros and custom lots, and the Traditional Data Sheet worksheet includes the Hermetic lots. See PDF reports.
Fortune and Spirit also anchor Zodiacal Releasing, which you can run in the Zodiacal Releasing calculator.
Related
For the wider traditional toolkit (profections, releasing, dignities), see Hellenistic astrology. For the history and meaning of each part, read the Arabic Parts guide. To try a single lot free, use the Part of Fortune or Lot of Spirit calculator.