Numerology compatibility is calculated three different ways from the same two birth dates: add the two life path numbers and reduce, subtract the smaller from the larger, or look the pair up in a chart. The three disagree. A 合盘, this method's combined chart, also adds, then folds the total into twelve pairings.
TL;DR
- One pair of birth dates gets three verdicts: 60% from the add table, 95 out of 100 from the subtract table, and a single cell in a lookup chart. No rule reconciles them.
- The number the add method reads is the root number of a 合盘. I checked 1,123,984 sampled pairs of birthdays against the code and found no exception.
- That root is one of twelve numbers in a 合盘. Two couples with the same two life path numbers got two charts in which all twelve slots differ.
- Only the add route extends to three or more people; the subtract and lookup methods stop at two.
How is numerology compatibility calculated?
From two birth dates, by one of three routes, and the route you pick decides the answer. Every route starts by turning each date into a life path number: the digits of the whole birth date added together and reduced to a single digit. For 14 March 1990 that is 1+4+0+3+1+9+9+0 = 27, then 2+7 = 9. For 3 January 1988 it is 0+3+0+1+1+9+8+8 = 30, then 3+0 = 3. In this method the same digit is called the root number, and it matched the plain digit-sum life path on all 13,149 birth dates from 1970 to 2005 (the plain version, with no exception for 11, 22 or 33).
Now the three routes on that pair, 9 and 3, run the way each one says to:
- Add: 9 + 3 = 12, then 1 + 2 = 3. The combined number is 3.
- Subtract: 9 − 3 = 6. The difference is 6.
- Look up: find the 9 row and the 3 column in a compatibility chart. The answer is one cell.
Then each route reads a score off its own table. The add table I read prints 60% for a combined number of 3. The subtract table I read prints 95分 for a difference of 6. Same two birth dates, 60 out of 100 and 95 out of 100. I ran all three by hand on this pair and then cast the 合盘 for it with the same code the app runs, which is where the rest of this article comes from.
Add, subtract or look up: what does each method actually compute?
Each one computes something different, so they are not three roads to one number. All three keep only the two life path numbers and discard the rest of both dates. This is what goes in and what comes out:
- Add
- Computes: the two life path numbers added and reduced to one digit, which the page calls the couple's 結合碼 (combined code), then a percentage for each of the nine possible codes: 40, 90, 60, 80, 75, 50, 85, 70 and 100 for codes 1 to 9.
- Source: beauty321, 20 November 2023, whose method sentence reads “8+8則為16，將這兩數相加，直到成為個位數：1+6=7，兩人的結合碼則是7” (8 plus 8 is 16; add those two digits until one remains, 1+6 = 7, and the couple's combined code is 7).
- People: two.
- Subtract
- Computes: the difference between the two numbers, larger minus smaller, so 0 to 8, then a score for each: 85, 80, 75, 50, 75, 45, 95, 60 and 55 for differences 0 to 8.
- Source: 爱星盘 (ixingpan.com), 5 July 2019, which says to subtract “以你们的灵数相减（大数减小数）” (subtract your numbers, larger minus smaller).
- People: two.
- A caution: other Chinese-language pages print a different subtraction table. Their search snippets, which I read on 30 September 2026, show 100分 for a difference of 2, 55 for 7 and 50 for 8, against 75, 60 and 55 above. Two tables for the same method already disagree.
- Look up
- Computes: nothing beyond the two life path numbers, which are in a grid of nine rows and nine columns: 81 cells, which is 45 distinct pairs once you ignore order.
- Sources: numerologist.com (Blair Andrews, published 4 May 2026, updated 23 September 2026): “The calculator compares your Life Path numbers, calculated from each date of birth”. And numerology.pardesco.com (Randall Morgan, updated 6 September 2026): “Find your row and your partner's column”.
- People: two.
- 合盘 (this method)
- Computes: from the birth dates themselves, not from the life path numbers: four seeds per person, summed across the people, then folded into a chart of twelve two-digit pairings.
- Source: the code that casts it, checked as described on the methodology page below.
- People: two to six.
A 合盘 (in this method, a compatibility chart that combines two or more birth dates into one chart describing the relationship rather than either person) is the only entry that looks at more than the two single digits.
Why do the add method and a 合盘 give the same number?
Because a 合盘 adds first and folds second, and reducing a sum gives the same digit as reducing the sum of the reduced parts. Here is the rule in words. Each person's date is cut into four seeds: the day's two digits added and reduced, the month's two digits, the first two digits of the year, and the last two. For 14 March 1990 the seeds are 5, 3, 1, 9. For 3 January 1988 they are 3, 1, 1, 7.
A 合盘 adds the seeds position by position across the people and reduces each sum: 5+3 = 8, 3+1 = 4, 1+1 = 2, 9+7 = 16, then 1+6 = 7. The combined seeds are 8, 4, 2, 7. Those go through the same fold a single chart uses. The chart's root number is the four seeds added and reduced: 8+4+2+7 = 21, then 2+1 = 3.
A single person's root number is their own four seeds added and reduced. So the combined root is everyone's seeds added and reduced, which is the same as everyone's roots added and reduced: 9 + 3 = 12, then 3. That is the number the add method reads a percentage off. The day master, this method's name for the chart's first seed, follows the same rule: 5+3 = 8 for the two day masters, and 8 is the combined chart's day master.
I did not trust the argument alone. I ran it against the code that casts the 合盘, on 1,123,984 pairs sampled from the 13,149 birth dates between 1970 and 2005 (every seventh date against every eleventh date after it). The combined root equalled the reduced sum of the two roots on every pair, and the combined day master equalled the reduced sum of the two day masters on the same pairs. How we check the arithmetic sets out the rest of the checking process. The consequence is short: the add method's number is not a rival to a 合盘. It is the 合盘's root, one number out of twelve.
If the root is the same, why is the chart different?
Because the root keeps one thing about the pair, the total of their digits, while the chart keeps the four seeds behind it. Take a second pair, 5 June 1987 (root 9) and 22 December 1985 (root 3). Add: 9 + 3 = 12, then 3. Subtract: 9 − 3 = 6. Lookup: the same 9-and-3 cell. All three methods answer exactly as they did for the first pair.
The 合盘 does not. The seeds are 5, 6, 1, 6 and 4, 3, 1, 4, so the combined seeds are 5+4 = 9, 6+3 = 9, 1+1 = 2 and 6+4 = 10, then 1. That gives 9, 9, 2, 1, a root of 9+9+2+1 = 21, then 3, and a day master of 9 instead of 8. The twelve pairings, in the app's slot order:
- 14 March 1990 and 3 January 1988
- Twelve pairings: 84, 27, 39, 27, 27, 36, 79, 93, 33, 83, 33, 36.
- 5 June 1987 and 22 December 1985
- Twelve pairings: 99, 21, 93, 99, 54, 63, 13, 33, 36, 99, 93, 33.
Read slot by slot, none of the twelve match. A percentage read off one number cannot be the whole of that chart. How many charts can one root pair produce? In the same sample, a 3-and-5 couple produced 252 distinct twelve-pairing charts, and across all 45 possible root pairs the count ran from 235 to 252. A sample is a fraction of every possible pair, so the true counts are higher, not lower. How the fold turns four seeds into twelve numbers is in what your life path number leaves out.
Can numerology compatibility be calculated for three or more people?
Only by the add route. Add the three roots from the worked dates, 14 March 1990 (9), 3 January 1988 (3) and 5 June 1987 (9): 9 + 3 + 9 = 21, then 3. In this method the seeds are added across all three: 5+3+5 = 13, then 4; 3+1+6 = 10, then 1; 1+1+1 = 3; 9+7+6 = 22, then 4. The combined seeds are 4, 1, 3, 4, the root is 4+1+3+4 = 12, then 3, matching the add total, and the day master is 4.
The subtract method needs a larger and a smaller number, and the lookup chart needs a row and a column, so both stop at two people. This method's combined chart takes two to six.
Is a high score good?
A high score means only that a table printed a high number. The same pair of dates read 60% on one table and 95 out of 100 on another, and two subtraction tables print 75 and 100 for the same difference of 2. The lookup chart says of its own numbers that “the scores are assigned numerology ratings, not measured probabilities of relationship success” (numerology.pardesco.com, updated 6 September 2026). I read every score in this article that way.
This method's 合盘 prints no score. It prints twelve numbers, and it does not treat any of them as good or bad: the method reads each pairing as having a healthy way of relating and an unhealthy one, which the 合盘 section of the post on 合道 sets out. That is a statement of what the method says, not a prediction, and not advice about anyone's relationship.
What this article does not tell you
What any number, pairing or root means, in any of the three methods or in this one. The personality text on the pages quoted above belongs to their publishers. The readings this method attaches to a combined chart are copyrighted practitioner material, so they are not on this site's public pages, and the app also reads the chart's twelve pairings and a business variant of it. What is here is the arithmetic: what goes in, what is added, and what comes out.
Fold two dates of birth in the free calculator, one at a time. It works out each date's root number and day master in your browser and shows the arithmetic behind both, which is everything the add and subtract methods need. The combined chart itself is cast inside the account's Numerology module, for two to six people at one Credit per person. That module is not part of the Free plan; it is switched on by request on WhatsApp.
FAQ
How is numerology compatibility calculated?
Three ways from the same two birth dates: add the two life path numbers and reduce the total, subtract the smaller from the larger, or look the pair up in a chart. They give different answers. A 合盘 adds the birth dates' seeds and folds the sum into a chart of twelve pairings.
Do you add or subtract the two life path numbers?
Both methods exist and they disagree. For 9 and 3, adding gives 3 and subtracting gives 6, and the tables read 60% and 95 out of 100. Neither is the 合盘, which adds the birth dates' four seeds instead.
What is a 合盘 in numerology?
In this method, a chart that combines two to six birth dates into one. Each person's four seeds are added position by position and folded like a single chart, giving a root number, a day master and twelve two-digit pairings that describe the relationship, not either person.
Can two couples with the same life path numbers get different charts?
Yes. Two couples who both had life path numbers 9 and 3 got two 合盘 charts in which all twelve pairings differ. In a sample of pairs, a 3-and-5 couple produced 252 distinct charts, and across all 45 root pairs the count ran from 235 to 252.
Does numerology compatibility work for three or more people?
Only the add route extends: the roots are added and reduced, 9 + 3 + 9 = 21, then 3. The subtract method and the lookup chart stop at two people. This method's combined chart takes two to six people.
