Cast your D16 (Shodasamsa), the sixteenth divisional chart of Vedic astrology, from date, time, and place of birth. The tool computes your D16 Lagna with a birth-time-confidence check, every planet’s segment, deity, D16 sign and house, and renders the chart in North or South Indian style. Uses the sidereal Lahiri ayanamsa, the same engine as our Kundli, and the BPHS modality rule.
100% private - the D16 calculation runs entirely in your browser. No birth data sent anywhere.
Supports 1900 onwards for better calculation reliability.
Birth time matters a lot here: a D16 segment is 1.875 degrees, so your D16 Lagna changes roughly every 7-8 minutes - about sixteen times faster than the ~2-hour D1 Lagna.
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astrology| Chart / harmonic | D16 (Shodasamsa, also Kalamsa), the sixteenth divisional chart |
|---|---|
| Division size | 16 equal segments of 1.875 deg (1 deg 52 min 30 sec) per sign |
| Start-sign rule | By modality: movable from Aries, fixed from Leo, dual from Sagittarius |
| Presiding deities | Brahma, Vishnu, Shiva, Surya (BPHS Ch. 6, 16), cycling; reversed for an even sign |
| Reachable signs | All twelve, across a whole chart |
| Classically read for | Conveyances (BPHS Ch. 7, 1-8); vehicles/comforts = later practice |
| D16 Lagna sensitivity | ~7-8 min of birth time per segment at Indian latitudes |
| Same-sign geometry | 18 of 192 cells, unevenly spread - no one-in-sixteen rule |
| Nodes | Rahu/Ketu ALWAYS share one D16 sign (forced by the modality rule) |
| Inputs | Date, time, and place of birth |
| Engine | Meeus VSOP87 + Lahiri ayanamsa; Rahu/Ketu = mean node (same engine as Kundli) |
| Privacy | 100% client-side; no birth data leaves your browser |
The Shodasamsa - also spelled Shodashamsa, and called the Kalamsa in the same verse - is one of the sixteen divisional charts (Shodasavarga) described in the Brihat Parashara Hora Shastra. Where the birth chart (D1) maps the whole life, each varga zooms into one domain, and the classical varga-use verse assigns the Shodasamsa to benefits and adversities through conveyances.
Like every varga, the D16 is a derived chart: it takes each planet’s exact sidereal longitude from the birth chart and re-maps it. Nothing new is observed in the sky. What makes the D16 distinctive is that its starting sign is fixed by the natal sign’s modality rather than by the natal sign itself - a rule it shares in form, but not in detail, with the Vimsamsa (D20).
Each sign is divided into sixteen segments of 1.875 deg. The verse rule: “Starting from Mesh for a Movable Rasi, from Simh for a Fixed Rasi and from Dhanu for a Dual Rasi, the 16 Shodashahsas... are regularly distributed.” The count then advances one sign per segment.
| Natal sign modality | Counting starts from |
|---|---|
| Movable (Aries, Cancer, Libra, Capricorn) | Mesh (Aries) |
| Fixed (Taurus, Leo, Scorpio, Aquarius) | Simha (Leo) |
| Dual (Gemini, Virgo, Sagittarius, Pisces) | Dhanu (Sagittarius) |
The four presiding deities repeat four times across the sixteen segments, in reverse order for an even sign:
| Segment numbers | Odd sign | Even sign |
|---|---|---|
| 1, 5, 9, 13 | Brahma | Surya |
| 2, 6, 10, 14 | Vishnu | Shiva |
| 3, 7, 11, 15 | Shiva | Vishnu |
| 4, 8, 12, 16 | Surya | Brahma |
Worked example: a planet at 10 deg of Taurus is in a fixed sign, so counting starts from Leo. 10 divided by 1.875 falls in the sixth segment (index 5), and five signs on from Leo is Capricorn - so its D16 sign is Capricorn. Each varga in the family carries its own rule: the Drekkana uses a uniform trine, the Chaturthamsa walks the kendras, the Dwadasamsa counts forward from the sign itself, and the D16 counts from a modality-selected seed.
This is the property most often mistaken for a calculation error, so it is worth stating plainly. Rahu and Ketu are always exactly opposite, six signs apart. Move six signs along the zodiac and the modality is the same again - Aries and Libra are both movable, Taurus and Scorpio both fixed, Gemini and Sagittarius both dual. The two nodes therefore start their count from the same sign, sit at the same degree within their own signs, and land on the same segment number. The result is the same D16 sign, in every chart.
The same arithmetic applies to any two bodies six signs apart at the same degree, and it is independent of the node model: mean node or true node, the co-location holds. In the birth chart the nodes remain opposite as usual.
The varga-use passage of the Brihat Parashara Hora Shastra (Ch. 7, 1-8) lists what each divisional chart is consulted for. Its wording for this chart is benefits and adversities through conveyances. That is the classical claim, and it is the only domain claim this page makes.
Modern practice commonly widens this to vehicles, comforts, luxuries and general happiness. That reading is later practice, not the verse’s own wording, and we label it as such rather than presenting the two as one tradition. This tool computes the chart; it does not interpret it.
This version computes the D16 chart, houses (whole-sign from the D16 Lagna), the segment deities, and the birth-time-confidence checks. It does not interpret the chart, it does not read houses for vehicle or comfort outcomes, and it ships no predictions and no remedies.
The Shodasamsa, also called the Kalamsa, is the sixteenth divisional chart (varga) of Vedic astrology. Each 30-deg sign is divided into sixteen segments of 1 deg 52 min 30 sec, and every planet is re-mapped to a new sign based on which segment it occupies. The classical varga-use verse in the Brihat Parashara Hora Shastra assigns this chart to benefits and adversities through conveyances. It is read alongside the birth chart (D1), not instead of it.
By Brihat Parashara Hora Shastra Ch. 6, 16: counting starts from Aries for a planet in a movable sign, from Leo for a fixed sign, and from Sagittarius for a dual sign, then advances one sign per segment. So the starting point depends on the natal sign's modality, not on the natal sign itself - all four movable signs share one mapping, all four fixed signs another. This tool applies the rule to each planet's exact sidereal longitude from the birth chart.
The Brihat Parashara Hora Shastra's varga-use verse assigns the Shodasamsa to benefits and adversities through conveyances - those translated words are the classical claim, and they are all this page asserts. Popular practice reads the D16 for vehicles, comforts and luxuries generally; that is a later interpretive gloss on the same chart, and we name it as such rather than presenting it as the verse's own wording.
Because the rule forces it. The nodes are always exactly opposite, six signs apart. Six signs later the modality repeats, so both nodes get the same starting sign and the same segment number, and therefore the same D16 sign. This happens in every chart, and it does not depend on whether a calculator uses the mean or the true node. In the birth chart they remain opposite as usual; it is only the D16 mapping that brings them together.
The Brihat Parashara Hora Shastra names Brahma, Vishnu, Shiva and Surya, cycling four times across the sixteen segments for a planet in an odd sign, and in the reverse order for an even sign. This tool shows the deity for each planet's segment; it does not attach any predictive meaning to them, because the classical text assigns the names without interpretation.
The ascendant crosses one 1.875-deg segment in roughly 7 to 8 minutes of clock time at Indian latitudes, against about two hours for a D1 Lagna sign. A birth time recorded to the nearest five or ten minutes is therefore not precise enough to fix the D16 Lagna. This tool reports how many minutes your entered time sits from the nearest D16 Lagna boundary, and flags any planet sitting within about 0.01 deg of a segment edge.
No, and it is not even evenly distributed. Because the count starts from a modality-fixed sign rather than from the natal sign, only 18 of the 192 sign-and-segment combinations map back to the starting sign: two segments for Aries, Cancer, Leo, Scorpio, Sagittarius and Pisces, and one for the other six signs. There is no tidy one-in-sixteen rule. The classical term vargottama refers to the D1/D9 correspondence, not the D16.
Both - use the North Indian (diamond) / South Indian (square) toggle above the chart; both draw the same D16 (Shodasamsa) placements. In the North Indian format the houses are fixed with the Lagna at the top and the signs rotate; in the South Indian format the signs are fixed in the grid and the ascendant is marked in its box. Pick whichever regional format is more familiar.
No. It computes the classical D16 chart and reports what traditional sources say the chart is consulted for - the varga-use verse assigns it to benefits and adversities through conveyances, and later practice reads it for vehicles and comforts. It makes no predictions about your purchases or your life, it does not tell you what will happen to you, and it offers no remedies, gemstones, or rituals.
This page is the canonical surface for these terms: D16 chart, Shodasamsa, Shodashamsa, and Kalamsa. They all refer to the sixteenth divisional chart described above.