MDXL is the Roman numeral for 1,540 — 1000 + 500 + 40.

How do you write 1540 in Roman numerals?

Take the largest value that fits and repeat until nothing is left: M (1000), then D (500), then XL (40). That gives MDXL.

1,540 in Roman numerals

MDXL

Number (1–3,999 for numerals)

Roman numeral

1,540 is written MDXL in Roman numerals. That is 3 symbol groups added together, reading left to right from the largest value down.

How it breaks down

MDXL = 1000 + 500 + 40 = 1,540
Group	Value	Subtraction	Running total
M	1,000	—	1,000
D	500	—	1,500
XL	40	L − X	1,540

Why the smaller symbol comes first

MDXL uses subtractive notation in one place: XL means L minus X, or 40. A smaller symbol placed before a larger one is subtracted from it rather than added, which is why IX is nine and not eleven.

Only six such pairs are valid — IV, IX, XL, XC, CD and CM. That restriction is what makes the notation unambiguous: IIII and IC both look like they should work, but neither is standard, and only one spelling of any number is correct.

The symbols

Symbol	Value	Used here
I	1	no
V	5	no
X	10	yes — 1×
L	50	yes — 1×
C	100	no
D	500	yes — 1×
M	1,000	yes — 1×

The same number, other ways

In words: One thousand five hundred forty
Roman numeral: MDXL
Symbol count: 4 characters
Binary: 11000000100
Hexadecimal: 604

The numbers either side

Number	Roman numeral
1,538	MDXXXVIII
1,539	MDXXXIX
1,540	MDXL ←
1,541	MDXLI
1,542	MDXLII

Common questions

What is 1540 in Roman numerals?: 1,540 is MDXL.
What does MDXL mean?: MDXL is the Roman numeral for 1,540 — 1000 + 500 + 40.
How do you write 1540 in Roman numerals?: Take the largest value that fits and repeat until nothing is left: M (1000), then D (500), then XL (40). That gives MDXL.

Sources

Calculated on this page — At One Place

How these figures are compiled and checked