Compare astrocartography maps
If two astrocartography maps look different, first match the birth moment, birthplace, selected destination, and the kind of result you are comparing. Then compare the same planet and angle with equivalent display and method settings. In AstroCarto, a map line, a relocated house, a city assessment, and a report verdict answer different questions. Record the remaining difference before deciding that either tool calculated it incorrectly.
Are both tools using the same birth moment and coordinates?
Start from the original birth record. Enter the recorded local time in a local-time field; use UTC only when the other field explicitly requests it. Where a tool shows its converted UTC, compare that as well as the clock time. Matching “12:00” is insufficient if one result means local time and another means UTC.
| Field to match | What to check | If it does not match |
|---|---|---|
| Birth date and time | Full date, hour and minute, including AM/PM where used | Correct the identifiable entry mistake and calculate again. Keep uncertain time marked uncertain instead of changing it to make two maps agree. |
| Birthplace | Full place name, country, and actual latitude/longitude | Resolve a same-name city or coordinate mismatch. Do not replace the birthplace with the destination. |
| Timezone and daylight saving | The birthplace's historical local zone and the resulting UTC, where available | Check the conversion basis; do not both convert the time yourself and let a local-time form convert it again. |
| Destination or selected point | The city coordinate or clicked point used for the distance or relocated chart | Compare the same point. A nearby click, a city centre, and an address can be different selections. |
| Time status | Known time versus estimated or unknown time | Keep the limitation attached to both results. Agreement between guessed inputs would not verify the actual birth time. |
Use birthplace and timezone checks when the conversion or matched place is unclear. If the time is not known reliably, follow unknown-time guidance before treating the comparison as precise.
Worked example: a 15-minute input difference changes the same line
This synthetic example was calculated for this tutorial using AstroCarto's map calculation. Both rows use 15 January 1990, London at 51°31′ N, 0°8′ W, timezone Europe/London, and Paris at 48.85° N, 2.35° E. The time is treated as known and only Sun is visible. Only the birth time changes.
| Birth time | Resolved UTC on 15 January 1990 | Sun MC distance from the same Paris point |
|---|---|---|
| 12:00 | 12:00 UTC | About 0.4 km |
| 12:15 | 12:15 UTC | About 274.6 km |
If the original birth record confirms 12:00, use the first row as the reference and correct the 12:15 input before comparing again. If it confirms 12:15, use the second row instead. The map interface can round these calculated distances to 0 km and 275 km, so check the display precision as well as the input.
The two rows are separate input scenarios, not two verdicts about an unchanged chart. The difference is already explained by an unmatched time; it is not evidence of disagreement between two calculation engines. These distances belong to this example, not a universal kilometres-per-minute rule.
For your own comparison, first confirm the recorded time. Generate the map with that input, make the same planetary lines visible, and check the same city or point again. Record which mismatch disappeared and which remains. Do not choose the time that produces a more attractive location result.
Am I comparing a map line, a relocated chart, or an interpretation?
Identify the output before comparing its numbers. A house number and a distance in kilometres cannot be checked as though they were the same result.
| Output | Compare with | What it does not establish by itself |
|---|---|---|
| Ordinary planetary map line | The same planet and angle: AS/ASC, DS/DSC, MC, or IC, at the same birth moment | A line's colour or appearance does not establish the person's best city. |
| Relocated chart | The same birth instant, destination coordinates, chart settings, and house system | A different house number alone does not show that an ordinary map line moved. |
| City check, discovery, or comparison | The same workflow, person, goal, cities or search scope, and available evidence | Different candidate pools or goals need not produce the same order. |
| Report or AI interpretation | Its original input version, evidence, question, and report scope | Different wording alone does not identify a difference in the calculated line geometry. |
Recorded comparison: check the fields before judging the result
An archived 15 October 2026 tutorial comparison used synthetic London birth details, 15 January 1990 at 12:00, and a Paris relocation chart in Astro-Seek and AstroCarto. These are dated teaching records; check the settings shown in your own current result.
| Recorded field | Astro-Seek record | AstroCarto standalone relocation record |
|---|---|---|
| Birth instant | 12:00 GMT / UT | 12:00 UTC |
| London coordinates | 51°31′ N, 0°8′ W | 51.5074° N, 0.1278° W |
| Paris coordinates | 48°51′ N, 2°21′ E | 48.85° N, 2.35° E |
| House system | Placidus | Whole Sign Houses |
| Sun house at birth → after relocation | 10 → 9 | 9 → 9 |
The Paris coordinates express the same point in different formats, and the recorded birth instants match. However, the London coordinates and house systems differ. The correct conclusion is that the house comparison is not yet aligned. Match those settings before investigating anything left over; the table does not prove that either product is more accurate or that the house system explains every remaining numerical difference.
Read the method label on the particular result. AstroCarto's standalone relocation calculator uses Whole Sign houses; its Personal Report has a separate relocated-chart profile with Placidus and Whole Sign comparison. Do not assume that every chart or report uses one house format. Nor should a house-number difference be treated as a change in ordinary map-line geometry.
For choosing a product by workflow rather than investigating a discrepancy, use the Astro-Seek comparison or Astro.com comparison. Those pages answer a different question from this check.
Which display and method differences should I check next?
Once the input and output type match, isolate one remaining difference. Compare named evidence rather than trying to align every colour and curve in two screenshots.
| What still differs | Check next | A useful conclusion or next action |
|---|---|---|
| One map shows fewer lines | Visible planets, angle types, additional objects, and access to the displayed layer | Enable the same available subject. A hidden line is a display difference; it is not proof that the calculation omitted that planet. |
| A familiar label looks different | Planet name and angle; AS and ASC describe the rising angle, DS and DSC the setting angle | Use the full label to match the subject. Do not use colour alone to identify a line across products. |
| One view contains more curves or bands | Ordinary angular lines versus aspect lines, Paran latitude bands, or local-space directions | Record each mode's name and compare equivalent objects. A Paran-pair distance is not automatically an ordinary-line distance. |
| A line and a zodiac chart position appear inconsistent | Whether the method uses the planet's spatial position or an ecliptic projection | Planetary latitude can matter to the map/chart distinction. Record the method rather than assuming a planet near a chart angle must put an identical line through that point. |
| Two distances differ | Exact selected point, planet-angle, distance definition, units, and rounding | Compare the numerical evidence for the same object. A rounded display or a different city coordinate should be identified before investigating deeper calculation differences. |
| The numeric line evidence matches but the recommendation differs | Goal, interpretation rules, candidate list, and report version | Treat this as an interpretation or workflow question first. Ask which evidence supports the different advice rather than assuming that the line itself was calculated differently. |
The AstroCarto calculation method describes the input-to-result workflow. For display controls, the interactive map guide explains visible planets and selection. These help you distinguish the settings you can change from a method that needs clarification; do not look for a switch that your tool does not offer.
Worked comparison: check where a distance is measured from
On 4 November 2026, we checked an AstroLina map against AstroCarto's current map calculation with synthetic birth details: 15 January 1990 at 12:00, London at 51.509° N, 0.126° W, and Europe/London. Both resolve to 12:00 UTC. We compared the ordinary Sun MC line, using AstroLina's Celestial / In Mundo settings, and fixed the destination at Paris, 48.85° N, 2.35° E.
AstroLina initially showed 171 km with a distance label referring to the natal point. AstroCarto's calculation gave about 0.4 km from Paris. Those numbers measured from different places: the London birthplace and the Paris destination. Moving the map view to Paris did not, by itself, change the distance reference.
| Comparison step | AstroLina map | AstroCarto calculation |
|---|---|---|
| Before matching the reference | 171 km from the natal point in London | About 0.4 km from the Paris point |
| Make the comparison equivalent | Place a pin at 48.85° N, 2.35° E | Keep the same Paris point and birth input |
| Read Sun MC from that point | The popup now shows 0 km from the pin | About 0.4 km, which rounds to 0 km |
| Inspect the remaining line position | About 2.3462° E in the drawn map data | About 2.3449° E in the calculated geometry |
To repeat this check, keep the birth input unchanged. In AstroLina, place a destination pin by double-clicking the intended point, verify its coordinates, and read the Sun MC popup again. Check that its distance refers to the pin. In AstroCarto, generate the map with the same birth input, select the same destination point, and read its Sun MC evidence. Compare that field, rather than a nearby label or a distance from the birthplace.
Matching the reference point explains the large distance mismatch in this example. The whole-kilometre results agree, but the recorded meridians still differ by about 0.0013°. The decimal longitudes above come from map data and calculation, not decimal readouts printed by both interfaces. Keep that remaining difference if you need a closer method check; this example does not establish its cause or prove that every line is identical. A displayed 0 km also does not mean an exactly zero distance.
A useful comparison note is: “Input and UTC checked; destination coordinates matched; comparing Sun MC ordinary lines. Visible planets now match. Remaining question: these two distances still differ at the same selected point.” Replace the subject and remaining question with your actual evidence. If the only unresolved setting is a chart's house system, keep the inquiry about that chart rather than reporting a map-line error.
What should I provide when a difference remains unexplained?
Prepare one reproducible question. Keep the original input and both results before recalculating, then collect:
- The tool and output type on each side, plus the date you obtained the results.
- Birth date, recorded local time, birthplace coordinates, time status, timezone, and converted UTC if shown.
- The same destination coordinates and the exact planet-angle or chart field you are checking.
- Visible layers, mode, house system where relevant, units, and the numerical values that differ.
- Screenshots or copied result text showing the inputs, labels, and disputed field, followed by the checks you already completed.
For example: “After aligning the UTC and Paris point, I still see different Sun MC distances. These are the two values and the visible settings. Can you explain the remaining difference?” That is more actionable than “the maps look wrong.” If the earlier field audit still shows different birth coordinates or house systems, report those as unresolved conditions instead of claiming a fully matched calculation.
Use Contact support for an AstroCarto result you cannot explain. Remove unrelated account, purchase, and other people's details from screenshots you post publicly; provide personal comparison details through the private support route when needed. A shared result link can also contain birth data, so inspect what it includes before posting it.
Generate your map with the checked input when you are ready to repeat the comparison. Keep the remaining question attached to the result; successful checking can explain a difference without making every interpretation identical.