Digital SAT Math Formulas You Need to Know (2026)

Updated 2026-07-23

The Digital SAT Math section gives you a built-in reference sheet with common geometry formulas, so you never have to memorize those. But the reference sheet does not include many of the algebra, statistics, and coordinate-geometry formulas you'll actually need to move quickly.

This guide splits the essential formulas into two lists: the ones provided for you, and the ones you should commit to memory. Learn the second list cold and you'll save time on nearly every Math module.

Practice free Digital SAT questions

Formulas provided on the reference sheet

These appear in the on-screen reference during the test, so recognition matters more than memorization:

  • Area of a circle: A = πr²
  • Circumference of a circle: C = 2πr
  • Area of a rectangle: A = lw
  • Area of a triangle: A = ½bh
  • Pythagorean theorem: a² + b² = c²
  • Special right triangles: 30-60-90 (sides x, x√3, 2x) and 45-45-90 (sides x, x, x√2)
  • Volume of a box: V = lwh
  • Volume of a cylinder: V = πr²h
  • Volume of a sphere: V = (4/3)πr³
  • Volume of a cone: V = (1/3)πr²h
  • There are 360 degrees (2π radians) in a circle; the sum of a triangle's angles is 180°.

Formulas you must memorize (not provided)

These are not on the reference sheet and show up constantly:

  • Slope: m = (y₂ − y₁)/(x₂ − x₁)
  • Slope-intercept form: y = mx + b
  • Point-slope form: y − y₁ = m(x − x₁)
  • Quadratic formula: x = (−b ± √(b² − 4ac)) / (2a)
  • Vertex form of a parabola: y = a(x − h)² + k, vertex (h, k)
  • Distance between two points: d = √((x₂ − x₁)² + (y₂ − y₁)²)
  • Midpoint: ((x₁ + x₂)/2, (y₁ + y₂)/2)
  • Average (mean) = sum of values ÷ number of values
  • Percent change = (new − old)/old × 100%
  • Exponential growth/decay: y = a(1 ± r)ᵗ
  • Equation of a circle: (x − h)² + (y − k)² = r², center (h, k), radius r
  • SOH-CAH-TOA: sin = opp/hyp, cos = adj/hyp, tan = opp/adj

How to actually use them

Formulas only help if you recognize when to reach for them. The fastest way to build that instinct is spaced practice: do a few mixed Math questions daily, and every time you miss one, write down which formula would have unlocked it. Our free adaptive Math practice tags every question by skill so you can see exactly which formulas you're weak on.

Frequently Asked Questions