mg/l to ug/l Converter
A water test that reads 0.8 mg/L is the same as 800 ug/L.
Quick answer: Multiply the mg/L by 1,000. For example, 0.8 mg/L is 800 ug/L, 8 mg/L is 8,000 ug/L and 80 mg/L is 80,000 ug/L.
The mg/L to ug/L formula
Micrograms per litre equal milligrams per litre times 1,000.
One milligram is 1,000 micrograms, and the litre stays the same.
Take 0.8 mg/L. 0.8 × 1,000 gives 800 ug/L.
Take 8 mg/L. 8 × 1,000 gives 8,000 ug/L.
Why the factor is 1,000
A milligram is one thousandth of a gram and a microgram is one millionth of a gram, so 1 mg is 1,000 ug. The volume in litres is the same on both sides, so the factor stays 1,000.
In dilute water, ug/L is used as the same number as ppb (Wikipedia: Parts-per notation).
How to convert mg/L to ug/L step by step
- Read the concentration in mg/L.
- Multiply it by 1,000.
- Write ug/L after the answer.
- Read ng/L in the last column if you need it.
Example 1: 0.8 mg/L
- Start with 0.8 mg/L.
- 0.8 × 1,000 = 800.
- The concentration is 800 ug/L.
0.8 mg/L = 800 ug/L
Example 2: 8 mg/L
- Start with 8 mg/L.
- 8 × 1,000 = 8,000.
- The concentration is 8,000 ug/L.
8 mg/L = 8,000 ug/L
Example 3: 80 mg/L
- Start with 80 mg/L.
- 80 × 1,000 = 80,000.
- The concentration is 80,000 ug/L.
80 mg/L = 80,000 ug/L
Example 4: 4 mg/L
- Start with 4 mg/L.
- 4 × 1,000 = 4,000.
- The concentration is 4,000 ug/L.
4 mg/L = 4,000 ug/L
Example 5: 40 mg/L
- Start with 40 mg/L.
- 40 × 1,000 = 40,000.
- The concentration is 40,000 ug/L.
40 mg/L = 40,000 ug/L
Example 6: 1.6 mg/L
- Start with 1.6 mg/L.
- 1.6 × 1,000 = 1,600.
- The concentration is 1,600 ug/L.
1.6 mg/L = 1,600 ug/L
Round only at the end. Rounding in the middle of a sum adds small errors that grow.
mg/L to ug/L conversion table
| Milligrams per litre (mg/L) | Micrograms per litre (ug/L) | Nanograms per litre (ng/L) |
|---|---|---|
| 0.08 mg/L | 80 ug/L | 80,000 Nanograms per litre (ng/L) |
| 0.2 mg/L | 200 ug/L | 200,000 Nanograms per litre (ng/L) |
| 0.4 mg/L | 400 ug/L | 400,000 Nanograms per litre (ng/L) |
| 0.8 mg/L | 800 ug/L | 800,000 Nanograms per litre (ng/L) |
| 1.6 mg/L | 1,600 ug/L | 1,600,000 Nanograms per litre (ng/L) |
| 4 mg/L | 4,000 ug/L | 4,000,000 Nanograms per litre (ng/L) |
| 8 mg/L | 8,000 ug/L | 8,000,000 Nanograms per litre (ng/L) |
| 16 mg/L | 16,000 ug/L | 16,000,000 Nanograms per litre (ng/L) |
| 40 mg/L | 40,000 ug/L | 40,000,000 Nanograms per litre (ng/L) |
| 80 mg/L | 80,000 ug/L | 80,000,000 Nanograms per litre (ng/L) |
| 200 mg/L | 200,000 ug/L | 200,000,000 Nanograms per litre (ng/L) |
| 400 mg/L | 400,000 ug/L | 400,000,000 Nanograms per litre (ng/L) |
The highlighted row is the default of the calculator. The last column gives Nanograms per litre (ng/L).
A quick mental shortcut for mg/L to ug/L
Move the decimal point three places to the right. 0.05 mg/L becomes 50 ug/L.
Add three zeros to a whole number. 2 mg/L is 2,000 ug/L.
ug/L and ppb
In dilute water a litre weighs about a kilogram, so 1 ug/L is treated as 1 ppb (Wikipedia: Parts-per notation).
The match is an approximation. It slips if the liquid is not close to the density of water.
Why labs report in ug/L
Many trace substances in water are present at very low levels. A number such as 800 ug/L is easier to read than 0.8 mg/L.
The two numbers describe the same amount.
Going the other way
To turn ug/L into mg/L, divide by 1,000. So 250 ug/L is 0.25 mg/L.
The last column shows the value in ng/L, which is 1,000 times larger again.
Quick conversion answers
| Conversion | Result |
|---|---|
| 0.8 mg/L | 800 ug/L |
| 8 mg/L | 8,000 ug/L |
| 80 mg/L | 80,000 ug/L |
| 800 mg/L | 800,000 ug/L |
Where this conversion is used
Water testers move between mg/L and ug/L when they read lab reports.
Students practise metric prefixes with concentration units.
Common mistakes to avoid
- Moving the decimal two places. The factor is 1,000, so move it three.
- Dividing instead of multiplying. The ug/L number is the larger one.
- Mixing ug/L with ug/mL. The volume unit changes the answer by 1,000.
- Mixing up mg/L and mg/kg. They match only in dilute water.
Related converters
More values at a glance
0.016 mg/L is 16 ug/L. 0.24 mg/L is 240 ug/L. 0.6 mg/L is 600 ug/L.
1.2 mg/L is 1,200 ug/L. 2.4 mg/L is 2,400 ug/L. 3.2 mg/L is 3,200 ug/L.
12 mg/L is 12,000 ug/L. 20 mg/L is 20,000 ug/L. 160 mg/L is 160,000 ug/L.
Common trace levels
0.001 mg/L is 1 ug/L. 0.005 mg/L is 5 ug/L. 0.01 mg/L is 10 ug/L.
0.05 mg/L is 50 ug/L. 0.1 mg/L is 100 ug/L. 0.5 mg/L is 500 ug/L.
1 mg/L is 1,000 ug/L. 5 mg/L is 5,000 ug/L. 10 mg/L is 10,000 ug/L.
Reading a lab report
Say a report lists 0.025 mg/L of a metal. Multiply by 1,000 and you get 25 ug/L. A report that lists 0.3 mg/L is the same as 300 ug/L.
Bigger numbers work the same way. A level of 12 mg/L is 12,000 ug/L, so the ug/L figure looks much larger even though nothing has changed.
Now try the reverse. A reading of 450 ug/L is 0.45 mg/L, and a reading of 75 ug/L is 0.075 mg/L. Divide by 1,000 each time.
A quick size check helps. If you start with mg/L, the ug/L answer must be bigger. If you start with ug/L, the mg/L answer must be smaller.
A simple memory trick
Think of the prefix ladder. Milli is one thousandth and micro is one millionth, so each step down the ladder multiplies the number by 1,000.
Say it out loud once: mg/L to ug/L, times a thousand. That is all you need to remember.
Frequently asked questions
How many Micrograms per litre is 1 mg/L?
1 mg/L is 1,000 ug/L.
How many Micrograms per litre is 8 mg/L?
8 mg/L is 8,000 ug/L.
How many Milligrams per litre is 1 ug/L?
1 ug/L is 0.001 mg/L.
How many ug/L is 1 mg/L?
1 mg/L is 1,000 ug/L.
How do I turn ug/L into mg/L?
Divide the ug/L by 1,000.
Is ug/L the same as ppb?
In dilute water they are used as the same number.
Sources
- Wikipedia: Parts-per notation (en.wikipedia.org)
