Friendship Compatibility Calculator

Friendship Calculator

Friendship Compatibility Formula

Formula

\[P=\min\!\left(99,\max\!\left(25,\operatorname{round}\!\left(\frac{L}{2}+r(d_1+d_2)+r(m_1+m_2)+r(y_1+y_2)+G\right)\right)\right)\]

Where:

\(P\) — Your Friendship Strength, as a percentage.
\(L\) — the sum of the assigned values of all recognized Cyrillic letters in both names.
\(r(n)\) — repeated addition of a number’s digits until one digit remains.
\(d_1,d_2\), \(m_1,m_2\), and \(y_1,y_2\) — the two birth days, months, and years, respectively.
\(G\) — 2 if the selected genders match, or 1 if they differ.

The calculator halves the combined name value, adds three reduced date sums and the gender value, then rounds the total. It limits the displayed result to 25%–99%.

Friendship Compatibility – Calculation Example

Example: Enter Анна and Борис, with birthdays of January 15, 2000 and February 20, 2001. Select Female and Male. This example assumes the dates are read as entered.

Анна has a letter value of \(1+6+6+1=14\); Борис has \(2+7+9+1+1=20\). Their combined name contribution is \((14+20)/2=17\).

Reduce the combined days, months, and years separately: \(r(15+20)=r(35)=8\), \(r(1+2)=3\), and \(r(2000+2001)=r(4001)=5\). Different gender selections add 1.

\[P=\min(99,\max(25,\operatorname{round}(17+8+3+5+1)))=34\%\]

Result: Your Friendship Strength is 34%. It is an entertainment score, not a judgment about this friendship.

How to use the calculator

Enter your name in Your Name and the other person’s name in Friend's Name. Neither field can be empty.
Check Your Date of Birth and Friend's Date of Birth. Both date fields initially show a date 20 years before your visit, so replace them with the intended birthdays.
Choose an option in Your Gender and Friend's Gender. These selections contribute a small fixed amount to the calculation.
Calculate and read Your Friendship Strength as a percentage. You can change an entry and calculate again to see how the score changes.

What the friendship compatibility score means

The result is a number generated from the entries, not a test of how well two people get along. The same inputs normally produce the same result, so the score is not random. It does not consider shared experiences, trust, communication, or whether either person enjoys spending time together.

A higher percentage means only that the inputs produced a higher total under this particular rule. A 75% result does not mean a friendship has a 75% chance of succeeding, and a 34% result does not suggest a problem. Use the number as a conversation starter rather than a rating of either person.

The name calculation is especially important to interpretation: it recognizes the Cyrillic letters listed below, but not Latin letters. If you enter names using the English alphabet, their letters add nothing to the name value. The dates and gender selections can still produce a result, so the displayed percentage may look meaningful even though the names did not affect it.

How names and dates affect the result

The calculator converts names to lowercase and removes spaces before adding letter values. Each occurrence counts: a repeated letter contributes its value again. It combines both names before dividing the letter total by two; it does not calculate a separate score for each person. The recognized letters have these values:

Value	Cyrillic letters
1	а, и, с, ъ
2	б, й, т, ы
3	в, к, у, ь
4	г, л, ф, э
5	д, м, х, ю
6	е, н, ц, я
7	ё, о, ч
8	ж, п, ш
9	з, р, щ

For birthdays, the calculator adds the two days and reduces that sum to one digit. It does the same with the two months and the two full years. This differs from reducing each person’s birthday separately. If you want to explore a different name-and-birthday system, try the Numerology by Name and Date of Birth calculator.

Assumptions and practical limitations

The 25% minimum and 99% maximum are built-in limits. A result at either boundary may represent a calculated total outside that range; it is not an exact measurement rounded to the nearest percent. Matching gender selections add 2 instead of 1, but that rule is arbitrary and says nothing about whether people of any genders can be good friends.

The calculator reads dates through your browser. In some time zones, its date handling may interpret a selected date as the previous calendar day, which can change the score. If a worked calculation does not match the displayed result, this is one possible reason.

For another playful comparison, see the Love Strength Calculator. To explore a separate number-based result, try the Lucky Number Calculator. None of these scores can replace what you learn by talking with someone and spending time together.

Frequently Asked Questions

What is a good friendship compatibility percentage?

There is no scientifically defined good score for this calculator. A higher number only means the names, birthdays, and gender selections produced a higher result under its rules. It does not predict how close you will become or how long a friendship will last. Trust, kindness, and time spent together tell you much more.

Is there a shortcut for reducing the birthday sums by hand?

Yes. Add the digits of each combined day, month, or year total, repeating until one digit remains. For example, 47 becomes 4 + 7 = 11, then 1 + 1 = 2. A positive multiple of 9 reduces to 9, not 0. Reduce the day, month, and year totals separately before adding their results.

Will the score change if I swap my details with my friend's?

No, swapping the two complete sets of details should leave the score unchanged. The calculation combines both names, adds the two birth days, months, and years, and checks whether the gender selections match. None of those operations depends on who is entered first. Changing or mistyping an entry is different and may change the result.

Should I transliterate an English name into Cyrillic?

Use Cyrillic spelling if you want the name to contribute to this calculator's result. English letters are not assigned values, while recognized Cyrillic letters are. Transliteration is not unique, however: two plausible spellings may contain different letters and produce different scores. Choose a spelling consistently if you are comparing results for fun.

Can different birthdays produce the same friendship score?

Yes. Different date pairs can produce the same reduced day, month, and year sums. Even when those sums differ, rounding or the 25% and 99% limits can make the displayed scores identical. Matching results do not mean the birthdays have a special connection; they are a consequence of how this calculation groups numbers.

Why do I get 99% for several different names?

The result stops at 99% even if the calculated total is higher. Because every recognized letter adds to the name total, longer names can reach that limit more easily. Once the limit is reached, changing a name may change the underlying total without changing the displayed percentage. It does not indicate a perfect friendship.

Why does my hand calculation differ from the calculator's result?

First check that you combined both people's days, months, and full years before reducing each sum, and that you counted only recognized Cyrillic letters. Also check the selected dates: browser time-zone handling can sometimes shift a date by one calendar day. If the result is 25% or 99%, remember that the displayed value may have been limited.