About the Law School Index Calculator
This law school index calculator combines your LSAT score (120–180) and undergraduate GPA into a single admission index, the kind of number many law schools use to sort applications before a full file review. You can either set how much weight the LSAT gets on a 0–1000 scale, or enter a school’s own linear formula in the form Index = A × LSAT + B × UGPA + C.
Each law school that uses an index sets its own weights, usually derived from studies of how LSAT and GPA predicted first-year grades for its past students. Some schools publish their formula or index ranges in admissions materials. Enter those weights in custom mode to reproduce it, or use the weighting mode to explore how a heavier or lighter LSAT emphasis changes your standing.
The calculator also shows how many LSAT points equal a tenth of a GPA point under your chosen weights, and the LSAT score you would need to reach a target index. Use your LSAC-calculated cumulative GPA (on LSAC’s 4.33 scale) for the closest match to how schools see you.
With the default inputs, the your law school index is 782.56. Change any value above to recalculate instantly.
How to use the law school index calculator
- 1Enter your LSAT score and LSAC-calculated undergraduate GPA.
- 2Choose percentage weighting, or school formula if you know a school’s A, B and C values.
- 3Set the LSAT weight or enter the school’s multipliers and constant.
- 4Enter a target index to see the gap and the LSAT score that would close it.
- 5Use the table and chart to compare LSAT and GPA trade-offs.
Formula and method
In weighting mode, the LSAT is placed on a 0–1 scale across its 120–180 range and the GPA on a 0–1 scale against LSAC’s 4.33 maximum (an A+). The two are blended with the LSAT weight you choose and multiplied by 1,000, so a perfect record scores 1,000. A 60% LSAT weight is a common starting point because the LSAT usually predicts first-year grades somewhat better than GPA alone.
In custom mode you enter a school’s own linear index: the LSAT multiplier A, the GPA multiplier B and the constant C. The LSAT needed for a target solves the same formula for the LSAT score at your current GPA, rounded up to a whole point.
- w
- LSAT weight (0–1)
- UGPA
- Undergraduate GPA as calculated by LSAC (max 4.33)
- A, B, C
- A school’s LSAT multiplier, GPA multiplier and constant
Worked examples
LSAT 165, GPA 3.6, 60% LSAT weight
The LSAT is 45/60 of the way up its scale: 0.6 × 0.75 × 1000 = 450. The GPA is 3.6/4.33 = 0.831: 0.4 × 831.4 = 332.6. The index is 782.6, so reaching 800 at the same GPA needs an LSAT of 167.
Equal weighting, LSAT 170, GPA 3.9
With 50/50 weights, LSAT 170 contributes 0.5 × 833.3 = 416.7 and a 3.9 GPA contributes 0.5 × 900.7 = 450.3, for 867.0 — 67 points above an 800 target. Here 0.1 of GPA is worth about 1.4 LSAT points.
School formula: LSAT + 10 × GPA
With Index = 1 × LSAT + 10 × GPA, a 165 LSAT and 3.6 GPA give 165 + 36 = 201, just above a 200 target. In this formula one LSAT point equals 0.1 of GPA.
Frequently asked questions
What is a law school index?+
It is a single number that combines your LSAT score and undergraduate GPA with weights chosen by a law school, typically in the form A × LSAT + B × GPA + C. Schools use it to sort large applicant pools and sometimes to set presumptive admit or deny ranges.
How do law schools weight the LSAT versus GPA?+
Each school sets its own weights, usually from studies of how well LSAT and GPA predicted first-year grades for its past students. Most formulas give the LSAT somewhat more weight than GPA, but the exact balance varies by school.
What GPA do law schools use for the index?+
Most use the cumulative undergraduate GPA calculated by LSAC’s Credential Assembly Service, which converts every grade to a common scale where an A+ counts as 4.33 and includes repeated courses. It can differ from the GPA on your transcript.
How do I find a school’s index formula?+
Some schools publish their formula or index ranges in admissions materials or on their admissions pages, and admissions offices will sometimes share it on request. If you cannot find it, use the weighting mode to compare your profile on a neutral scale.
Is a higher LSAT or a higher GPA more valuable?+
Under this calculator’s default 60% LSAT weighting, 0.1 of GPA is worth roughly one LSAT point. Because you can still retake the LSAT but your GPA is mostly fixed by senior year, raising the LSAT is usually the more practical lever.