Example 1
- Diagonal e: 6
- Diagonal f: 8
24.00
e = 6 and f = 8 gives 24.00.
Rhombus area calculator
Type both diagonals. The calculator takes half of e times f and shows area in cm² or in², matching the unit switch.
A = e f / 2. A parallelogram is on the parallelogram area calculator. A rectangle is on the rectangle area calculator.
Result
Diagonal e (cm) and Diagonal f (cm). Area shows up here.
How it works
Rhombus area is half the product of the diagonals. The first card example, 6 and 8, is 24.00, because 48 divided by two. The neighboring 6 by 8 rectangle is 48 and does not split.
Rhombus diagonals meet at a right angle, and this formula uses that. Side 6 and height 8 on the parallelogram is 48, another calculator.
Equal diagonals 10 and 10 give 50.00. That is not a square of side 10: that square has area 100 and diagonals 10√2, not 10. The pair 8 and 8 gives 32.00. A thin rhombus 4 and 10 gives 20.00. Order of e and f does not matter: 5 and 12 is the same 30.00 as 12 and 5.
The calculator does not run when a diagonal is missing. Switching to inches relabels the result as in² and does not convert a typed 6. A rhombus side is not an input.
If you only know a and h, open the parallelogram. This calculator does not pull diagonals out of a side.
A triangle ½×6×8 is also 24, because the diagonals cut the rhombus, but the story is different. Here you stay with e f / 2. At 14 and 6 you get 42.00. At 16 and 12 you get 96.00.
How to use
- Type diagonal e, one diagonal between opposite vertices, in cm or inches.
- Type diagonal f perpendicular to e, in the same unit.
- Click Calculate. The result uses two decimal places and cm² or in².
- Do not type side a. Side times height is on the parallelogram card, not here.
- The 6 and 8 example is 24.00. That is not 48 from a 6 by 8 rectangle and not 48 from a = 6, h = 8.
Formula
A = (e × f) / 2
Not a × h.
A = ef/2 at e = 6 and f = 8
Half the product of the diagonals. e = 6 and f = 8 give 24.00. e = 10 and f = 10 give 50.00. Not a × h.
- A
- Area (e × f) / 2. 6 and 8 give 24.00. 5 and 12 give 30.00. 8 and 8 give 32.00.
- e
- First diagonal. 6 with f = 8 is 24. 10 with f = 10 is 50.
- f
- Second diagonal. 8 with e = 6. 12 with e = 5 is 30.00.
Examples
Example 2
- Diagonal e: 10
- Diagonal f: 10
50.00
e = 10 and f = 10 gives 50.00.
Example 3
- Diagonal e: 5
- Diagonal f: 12
30.00
e = 5 and f = 12 gives 30.00.
Example 4
- Diagonal e: 8
- Diagonal f: 8
32.00
e = 8 and f = 8 gives 32.00.
Example 5
- Diagonal e: 14
- Diagonal f: 6
42.00
e = 14 and f = 6 gives 42.00.
Example 6
- Diagonal e: 9
- Diagonal f: 12
54.00
e = 9 and f = 12 gives 54.00.
Example 7
- Diagonal e: 4
- Diagonal f: 10
20.00
e = 4 and f = 10 gives 20.00.
Example 8
- Diagonal e: 16
- Diagonal f: 12
96.00
e = 16 and f = 12 gives 96.00.
Frequently asked questions
Is this side times height?
No. Here you type diagonals. Side 6 and h = 8 on the parallelogram is 48. Diagonals 6 and 8 here give 24.00. Another formula, another calculator.
Why do 6 and 8 give 24, not 48?
Because of the half. 6 times 8 is 48, half is 24.00. A 6 by 8 rectangle stays 48 on its own card.
Are 10 and 10 a square of side 10?
No. Diagonals 10 and 10 give area 50.00. A square of side 10 has area 100 and diagonals 10√2, not 10.
What if I leave f empty?
Nothing is computed. Type the second diagonal or load 6 and 8. Empty f does not become a segment.
Must the diagonals be perpendicular?
The formula assumes a rhombus, so yes. A parallelogram without a right angle between diagonals is not in this calculator.
Can I mix centimeters and inches?
Not in one run. Both diagonals in cm or both in inches. The switch changes the label and does not convert numbers.
Does swapping e and f change 30.00?
No. 5 and 12 is the same as 12 and 5. The calculator does not sort the longer diagonal.
Why do 4 and 10 give 20.00?
To show a thin rhombus. Half of 40 is legal. The formula does not need e close to f.
Is a triangle ½×6×8 the same 24?
The number 24 matches half of a 6 by 8 rectangle. Here it is a rhombus from diagonals. Two stories; this calculator is the rhombus.
Is 9 and 12 equal to 54.00?
Yes. 9 times 12 is 108, half is 54.00. At 16 and 12 you get 96.00.
Knowledge sources
The calculator computes the same formula as the definition below.
Page updated in 2026.