Quadratic Equation Solver & Percentage Calculator Helper

Q: Can it handle complex roots?

Yep. If your discriminant is negative, the tool returns the roots in standard a + bi form so you don't have to deal with imaginary numbers by hand.

Q: What if a = 0?

Then it's not actually a quadratic — it's linear (bx + c = 0). The tool will let you know and won't try to force a square-root step.

Q: Does it show steps?

It shows the discriminant and both roots. Combined with the formula above, that's everything you need to write out the work for a homework page.

Q: Can I use decimals or fractions?

Decimals work directly. For fractions, convert with our fraction calculator first or just type the decimal equivalent.

Q: Is this free?

Totally free, no account needed. Use it as much as you want during finals week.

Quadratic Equation Solver — pairs nicely with our percentage calculator

Stuck on ax² + bx + c = 0 at 11pm the night before a test? Same. Our Quadratic Equation solver crunches the roots for you — real or complex — and shows the discriminant so you actually understand what's going on, not just the final number. Just like our popular percentage calculator handles those quick mental-math moments before class, this tool is built for the homework-grind, exam-cram, "wait-I-forgot-the-formula" kind of day. Type in your three coefficients, hit solve, and you're done. We also list the discriminant (b² − 4ac) so you can tell at a glance whether you're getting two real roots, one repeated root, or a complex pair

How to use Quadratic Equation Solver — pairs nicely with our percentage calculator

Plug in a, b, and c. Type the three coefficients from your equation ax² + bx + c = 0 into the input fields. Negative numbers and decimals are fine.
Hit Solve. Click the solve button and the tool runs the quadratic formula in the background — no setup, no sign-up.
Read the discriminant. Check the value of b² − 4ac. Positive means two real roots, zero means one repeated root, negative means complex roots.
Grab the roots. Copy x₁ and x₂ from the output. If the discriminant is negative, you'll get them in a + bi form.
Double-check your work. Substitute the roots back into your original equation to confirm. Great way to catch a sign error before turning in homework.

Frequently asked

What's the quadratic formula again?

x = (−b ± √(b² − 4ac)) / 2a. The tool uses this exact formula and just handles the arithmetic for you.

What does the discriminant tell me?

It's b² − 4ac. If it's > 0 you get two real roots, = 0 means one repeated root, < 0 means two complex roots. Teachers love asking about this.

Can it handle complex roots?

Yep. If your discriminant is negative, the tool returns the roots in standard a + bi form so you don't have to deal with imaginary numbers by hand.

What if a = 0?

Then it's not actually a quadratic — it's linear (bx + c = 0). The tool will let you know and won't try to force a square-root step.

Does it show steps?

It shows the discriminant and both roots. Combined with the formula above, that's everything you need to write out the work for a homework page.

Can I use decimals or fractions?

Decimals work directly. For fractions, convert with our fraction calculator first or just type the decimal equivalent.

Is this free?

Totally free, no account needed. Use it as much as you want during finals week.

Quadratic Equation Solver — pairs nicely with our percentage calculator

How to use Quadratic Equation Solver — pairs nicely with our percentage calculator

Frequently asked

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