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Law School Admission Index Calculator

Calculate an admission index from an LSAT score, LSAC undergraduate GPA and the A, B and C coefficients used by a particular law school. LSAC documents the general formula, but the coefficients and the way an index is used are school-specific.

UFBuilt and maintained by Umer Farooq, founder & developer of CalcsDone
Updated September 20, 2026Formula documented from LSAC sources
Enter your numbers
LSAC formula: Index = (A × LSAT) + (B × GPA) + C
Your scores
120–180
0–4.33
School-specific coefficients
Index = (A × LSAT) + (B × GPA) + C
Calculated index
Enter your LSAT, LSAC GPA and all three school-specific coefficients
  1. Enter valid values above to see the arithmetic.
Important: This calculator performs the LSAC-documented arithmetic only. It does not supply a school’s current coefficients, estimate admission probability, or determine how a school will use an index. LSAC says not all law schools use index formulas, and schools that do use them do not necessarily use them in the same way. Confirm current coefficients in information disclosed by LSAC or the law school. Calculations run locally in your browser.
How it works

What the Law School Admission Index Means

LSAC describes an admission index as a school-specific combination of LSAT score and undergraduate GPA.

The documented formula

LSAC states the calculation as Index = (A × LSAT) + (B × GPA) + C. The individual law school selects the constants.

Not every school uses an index

LSAC states that not all law schools use index formulas, and schools that do use them do not necessarily use them in the same way.

The index is school-specific

LSAC’s cautionary guidance says the index calculation is unique for each law school and is a starting point for applicant evaluation, not a complete admission decision.

Use the LSAC-calculated UGPA

LSAC standardizes undergraduate grades for CAS. Its conversion table includes 4.33 for an A+, so the LSAC GPA can differ from the GPA shown by a college.

Using the calculator

Where the Coefficients Come From

The calculator deliberately does not provide made-up school presets. LSAC’s Academic Summary Report documentation says the constants A, B and C are selected by individual law schools and may change. A calculation is meaningful only when you use the coefficients applicable to the school and reporting context you are evaluating.

If you do not have the coefficients, do not substitute another school’s values or an arbitrary example and interpret the result as an admissions signal. LSAC also cautions against placing excessive weight on the apparent precision of an index. For your GPA input, use the appropriate LSAC undergraduate GPA rather than assuming the GPA printed on your transcript is identical.

Worked examples

Admission Index Formula Examples

These examples demonstrate the arithmetic only. The coefficient sets are explicitly fictional and are not attributed to any law school.

Example 1

Fictional coefficient set A

LSAT / GPA165 / 3.70
A / B / C0.016 / 0.242 / −0.284
Index = 3.2514

(0.016 × 165) + (0.242 × 3.70) − 0.284 = 3.2514. This demonstrates the formula only.

Example 2

Fictional coefficient set B

LSAT / GPA160 / 3.50
A / B / C0.020 / 0.300 / −0.500
Index = 3.7500

(0.020 × 160) + (0.300 × 3.50) − 0.500 = 3.7500. The raw scale is determined by the coefficients.

Example 3

Why coefficients matter

LSAT / GPA170 / 3.90
A / B / C1 / 15 / 0
Index = 228.5000

(1 × 170) + (15 × 3.90) = 228.5. Do not compare this raw number with an index produced by a different formula.

Common mistakes

Admission Index Mistakes to Avoid

!

Using invented or outdated coefficients

Coefficients are school-specific and can change. Confirm the values relevant to the school before treating the result as meaningful.

!

Using the wrong GPA

LSAC calculates undergraduate GPA under CAS rules. It can differ from a college transcript GPA, so use the appropriate LSAC figure when the formula calls for it.

!

Comparing raw index numbers across formulas

Different coefficients create different numerical scales. A larger raw number from one formula is not automatically stronger than a smaller number from another.

!

Treating the index as an admission prediction

LSAC describes the index as a convenient starting point and warns against excessive reliance on its apparent precision. It is not an admission-probability calculator.

FAQ

Law School Admission Index FAQ

What formula does this calculator use?+
It uses LSAC’s documented structure: Index = (A × LSAT) + (B × GPA) + C.
Does every law school use an admission index?+
No. LSAC states that not all law schools use index formulas, and those that do do not necessarily use them in the same way.
Can this calculator tell me my chance of admission?+
No. It performs a school-specific arithmetic formula when you supply the coefficients. It does not estimate admission probability or replace a school’s admissions process.
Why does the GPA input allow 4.33?+
LSAC’s grade-conversion table assigns 4.33 to an A+. LSAC recalculates undergraduate grades under CAS rules, so its GPA can differ from a transcript GPA.
Can I compare index values from two different schools?+
Not by raw number alone. Different school-specific coefficients can produce completely different scales, so compare a result only in the context of the formula that produced it.
About this calculator

How This Calculator Is Maintained

UF

Umer Farooq

Founder & Developer, CalcsDone

The calculator documents its formula, assumptions and limitations and links to primary LSAC sources. No professional admissions credential or independent expert review is claimed.

Read the CalcsDone Methodology →
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Law School Admission Index References

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