All in One Math Calculator
Six calculators in one app — no ads, works offline.
$1.99 on both stores — one purchase, no ads, no subscription.
Six calculators, one board
Quadratic Equation Solver
Step by step
- Start from the quadratic formulax = −b ± b2 − 4ac2a
- Substitute a, b and cx = −(−2) ± (−2)2 − 4(1)(−15)2(1)
- Work out the discriminant, b² − 4acΔ = (−2)2 − 4(1)(−15) = 64
- The discriminant is a perfect square, so the roots are rational64 = 8
- Take the plus branchx₁ = 2 + 82 = 5
- Take the minus branchx₂ = 2 − 82 = −3
Also worth knowing
- Vertex
- (1, −16)
- Axis of symmetry
- x = 1
- Discriminant
- 64
- Parabola opens
- upward
- Factored form
- (x − 5)(x + 3) = 0
Fraction Calculator
Step by step
- The problem12+13
- Find the least common denominator of 2 and 3LCD = 6
- Rewrite both fractions over that denominator12 = 3613 = 26
- Add the numerators3 + 26 = 56
- The result is already in lowest termsgcd(5, 6) = 1
Sarrus Rule Calculator
Step by step
- Copy the first two columns to the right of the matrix22−5223153172.2672.2
- Multiply along the three diagonals going down-right, and add them2 × 1 × 6 + 2 × 5 × 7 + (−5) × 3 × 2.2
- That gives the positive part of the determinant12 + 70 + −33 = 49
- Multiply along the three diagonals going up-right, and add them7 × 1 × (−5) + 2.2 × 5 × 2 + 6 × 3 × 2
- That gives the part to be subtracted−35 + 22 + 36 = 23
- Subtract the second sum from the firstdet = 49 − 23 = 26
Base Converter
Step by step
- Give each digit its place value — powers of 2, right to left1×27 + 1×26 + 0×25 + 1×24 + 0×23 + 1×22 + 1×21 + 0×20
- Work out each term128 + 64 + 0 + 16 + 0 + 4 + 2 + 0
- Add them up110101102 = 21410
Area Calculator
Step by step
- Multiply width by heightA = w × h = 12 × 7 = 84
- Add both pairs of sidesP = 2(w + h) = 2(12 + 7) = 38
Rule of Three Calculator
Step by step
- Set the two ratios equal to each other100250 = 15x
- Cross multiply100 × x = 250 × 15
- Divide both sides by A to isolate xx = 250 × 15100 = 3750100
- Work out the divisionx = 37.5
What it does
All in One Calculator
Every calculator on this site, in one place. Switch between fractions, quadratic equations, 3×3 determinants, base conversion, area and the rule of three without leaving the page — and try each one before deciding whether the app is worth it.
Six tools, one app
Replaces six single-purpose calculators, and the ones added later are included.
No ads, ever
A one-time purchase rather than an ad-supported free app.
Works offline
Everything runs on-device, so it works in an exam hall or on a plane.
All future calculators
New calculators added to the app are included at no extra cost.
How it works
Three steps to an answer
Pick a calculator
Six tabs, one for each tool. Your last-used tool is remembered.
Enter your values
Each tool keeps the same clean layout, so there is nothing new to learn.
See the steps
Every tool shows its working, not just the final answer.
Guides
Learn the method, then check your work
Each guide walks through one kind of problem end to end, then drops the numbers straight into the calculator above.
Choosing a Maths Calculator App
What actually matters, and the things marketing pages tend not to mention.
Read the guide →Six Calculators for School Maths
What each one is for, and which topic it turns up in.
Read the guide →Why Offline Matters
Signal, speed, privacy, and the difference between local and cloud maths.
Read the guide →Checking Your Own Work
Substitute back, estimate first, and use a second method. Three habits.
Read the guide →Calculators and Exam Rules
Phones are never allowed. What that means for how you should practise.
Read the guide →One App Instead of Six
An honest comparison, including when the separate apps are the better choice.
Read the guide →In the app
What All in One Calculator looks like on your phone
The same calculator, built for touch — plus the AI explanation and dark mode that come with PRO.
FAQ
Questions people ask
What is included in All in One Calculator?
Six calculators in a single app: fractions, quadratic equations, 3×3 determinants by the rule of Sarrus, base conversion, area and perimeter, and the rule of three.
One app instead of six →Is All in One Calculator free?
No — it is a paid app, bought once with no ads and no subscription. Every calculator it contains is also free to use on this website.
Does it work offline?
Yes. All the calculations run on your device, so the app works with no internet connection at all.
Why offline matters →Will new calculators be added?
Yes, and they are included at no extra cost — the one purchase covers future calculators added to the app.
Should I get this or the individual apps?
If you need more than one or two of the calculators, All in One is the simpler choice and removes the ads. If you only ever need a single tool, the individual app for it is free to download.
How to choose →