Free Calculator Tool

Quadratic Formula Calculator

Solve any quadratic equation ax² + bx + c = 0. Get both roots with step-by-step solution.

Want to solve ANY math problem? Just take a screenshot.

Math.Photos handles algebra, calculus, geometry, statistics, and more — all from a photo or your handwritten notes.

20 free solves · no credit card · no account needed to start

Install

Solve ax² + bx + c = 0

a (x² coefficient)

b (x coefficient)

c (constant)

How It Works

The Quadratic Formula

For any equation ax² + bx + c = 0, the solutions are x = (-b ± √(b²-4ac)) / 2a. This formula works for all quadratic equations, whether they have real or complex roots.

The Discriminant

The discriminant (b²-4ac) determines the nature of roots: positive means two distinct real roots, zero means one repeated root, negative means two complex conjugate roots.

Step-by-Step Process

1) Identify a, b, c coefficients. 2) Compute the discriminant. 3) Take the square root. 4) Apply the formula for both + and - cases. 5) Simplify.

When to Use It

Use the quadratic formula when factoring is hard or impossible. It always works, unlike factoring which only works for "nice" numbers. It's essential for algebra, physics, and engineering.

Already did the work? Get it checked instead.

A calculator gives you an answer. It doesn't tell you which line of your working went wrong. Photograph your own steps — handwritten notebook, whiteboard, or a screenshot of an online assignment — and Math.Photos checks them line by line, then points at the exact step where the sign flipped.

Reads handwriting

Photo of your notebook, not a retyped expression.

Step-level verdict

"Line 3 dropped a negative", not just "wrong".

Teach Me mode

Questions that lead you to the fix, not the answer.

Install How the math checker works → First 20 checks free

Pricing

Start free — 20 solves, no card. Upgrade only when you run out.

Lite

$1.99 /month

50 solves/month

Enough for a weekly problem set.

Student

$4.99 /month

500 solves/month

Every assignment, all semester, plus Teach Me mode.

Pro

$9.99 /month

3,000 solves/month

Multi-device sync and LaTeX/PDF export.

Annual billing saves 37%. Cancel anytime — see full plan comparison.

Need more than a quadratic formula calculator?

Math.Photos solves any math problem from a screenshot — algebra, calculus, geometry, statistics, and more. With step-by-step explanations.