Example 1 — 2D midpoint
\(A(2,5)\), \(B(8,-1)\). \(\;M\big(\tfrac{2+8}{2},\tfrac{5+(-1)}{2}\big)=(5,2)\).
Check: \(d(M,A)=\sqrt{(5-2)^2+(2-5)^2}=\sqrt{18}=3\sqrt{2}\); \(d(M,B)=\sqrt{(8-5)^2+(-1-2)^2}=\sqrt{18}\).
For points A(x₁, y₁) and B(x₂, y₂), the midpoint is
M = ( (x₁ + x₂)/2 , (y₁ + y₂)/2 ). Enter any two points and tap Calculate.
((x₁+x₂)/2, (y₁+y₂)/2).M = ( (x₁ + x₂)/2 , (y₁ + y₂)/2 ). The preview shows your values substituted into the formula.
A Midpoint Formula Calculator computes the exact halfway point between two points in a plane or in space. Given endpoints \(A(x_1,y_1)\) and \(B(x_2,y_2)\), the midpoint \(M\) lies exactly at the center of segment \(\overline{AB}\), equidistant from both ends. The same idea extends naturally to three dimensions with \(A(x_1,y_1,z_1)\), \(B(x_2,y_2,z_2)\). This tool accepts integers, decimals, and fractions, and shows each arithmetic step so learners can follow the process. It also provides quick checks—like verifying equal distances from \(M\) to both endpoints—to build intuition and confirm correctness. All formulas render responsively with MathJax or math.js for clean, readable math on any device.
The midpoint is the coordinate-wise average of the endpoints. In vector form, \(M=\tfrac{A+B}{2}\). This simple average has powerful geometric meaning: it bisects the segment and is the center of symmetry between the two points. The calculator normalizes inputs (e.g., converts mixed numbers to improper fractions), computes component-wise means, and returns simplified exact results when possible. For numeric data, it also displays decimal approximations. An optional extension shows the internal-division formula (ratio form), illustrating that the midpoint is a special case of dividing a segment into a \(1{:}1\) ratio. The tool is useful in coordinate geometry, graphics programming, CAD, and physics problems that require centers, midpoints, or balanced locations between two positions.
2D midpoint: \[ M\!\left(\frac{x_1+x_2}{2},\ \frac{y_1+y_2}{2}\right) \]
3D midpoint: \[ M\!\left(\frac{x_1+x_2}{2},\ \frac{y_1+y_2}{2},\ \frac{z_1+z_2}{2}\right) \]
Vector form: \[ \mathbf{M}=\frac{\mathbf{A}+\mathbf{B}}{2} \]
Equidistance check (2D/3D): \[ d(M,A)=d(M,B)=\sqrt{\sum (\,\text{coord}_M-\text{coord}_{A/B}\,)^2} \]
Internal division (ratio \(r:s\)): \[ P=\left(\frac{r x_2+s x_1}{r+s},\ \frac{r y_2+s y_1}{r+s}\right)\quad\text{(midpoint when }r=s=1\text{)}. \]
\(A(2,5)\), \(B(8,-1)\). \(\;M\big(\tfrac{2+8}{2},\tfrac{5+(-1)}{2}\big)=(5,2)\).
Check: \(d(M,A)=\sqrt{(5-2)^2+(2-5)^2}=\sqrt{18}=3\sqrt{2}\); \(d(M,B)=\sqrt{(8-5)^2+(-1-2)^2}=\sqrt{18}\).
\(A(1,4,2)\), \(B(5,-2,6)\). \(\;M\big(\tfrac{1+5}{2},\tfrac{4+(-2)}{2},\tfrac{2+6}{2}\big)=(3,1,4)\).
\(A\!\left(\tfrac{1}{2},\tfrac{3}{4}\right)\), \(B\!\left(\tfrac{5}{2},\tfrac{7}{4}\right)\). \(\;M\!\left(\tfrac{1/2+5/2}{2},\tfrac{3/4+7/4}{2}\right)=\left(\tfrac{3}{2},\tfrac{5}{4}\right)\).
The coordinate-wise average of endpoints: \(M\big(\tfrac{x_1+x_2}{2},\tfrac{y_1+y_2}{2}\big)\) in 2D; extend with \(z\) for 3D.
Yes. Enter \(z\)-coordinates to compute \(M\!\left(\tfrac{x_1+x_2}{2},\tfrac{y_1+y_2}{2},\tfrac{z_1+z_2}{2}\right)\).
Absolutely. The tool simplifies exact fractions and also shows decimal approximations.
Yes. By definition, \(d(M,A)=d(M,B)\); the calculator can display this check.
Use \(m=\tfrac{a+b}{2}\) since 1D is just a special case of the 2D formula.
The midpoint equals that same point; the segment length is zero.
No. Averaging is symmetric: swapping endpoints yields the same midpoint.
Yes. The midpoint of a chord is its center along the chord and lies on the circle’s perpendicular bisector.
Exact arithmetic is used for rationals; decimals are rounded to your chosen precision if enabled.