The short answer: normal adult urine output is about 0.5 to 1 ml per kilogram of body weight per hour. At 70 kg that is roughly 35 to 70 ml an hour. Averaged across an ordinary day of drinking, most adults pass 50 to 80 ml an hour.
Because the range scales with weight, the same hourly amount can be normal for one person and low for another. Use the calculator for your own range, or the chart below.
Urine output per hour calculator
Enter your weight to see your normal hourly range. Add a measured amount to see your rate in ml/kg an hour.
Your normal range will appear here.
Normal urine output per hour by weight
| Body weight | Normal per hour | Floor (0.5 ml/kg) |
|---|---|---|
| 40 kg (88 lb) | 20-40 ml | 20 ml |
| 50 kg (110 lb) | 25-50 ml | 25 ml |
| 60 kg (132 lb) | 30-60 ml | 30 ml |
| 70 kg (154 lb) | 35-70 ml | 35 ml |
| 80 kg (176 lb) | 40-80 ml | 40 ml |
| 90 kg (198 lb) | 45-90 ml | 45 ml |
| 100 kg (220 lb) | 50-100 ml | 50 ml |
| 110 kg (243 lb) | 55-110 ml | 55 ml |
| 120 kg (265 lb) | 60-120 ml | 60 ml |
How to work out ml/kg an hour
- Measure every void over a set period, for example six hours.
- Add the volumes and divide by the number of hours: 280 ml over 6 hours is about 47 ml an hour.
- Divide by your weight in kilograms: 47 ÷ 70 kg is about 0.67 ml/kg an hour, inside the normal range.
Count the hours from your last void before the period starts, not from your first void inside it. Otherwise the first void includes urine made before the clock started. For the methods themselves, see how to measure urine volume.
Why the hourly rate changes through the day
Urine production is not steady. The kidneys make more while you are awake and drinking, and at night antidiuretic hormone cuts production sharply so that sleep is not interrupted. An hourly figure taken over a short window therefore reflects what you drank in the hours before, more than how your kidneys are working. A rate over a longer period, or a full 24-hour total, gives a steadier picture.
When low output matters: the KDIGO thresholds
In hospital, hourly output is the number clinicians watch, which is why patients after surgery or in intensive care often have it measured through a catheter. Under the international KDIGO guideline, output below 0.5 ml/kg an hour for at least 6 hours is one of the criteria that define acute kidney injury, alongside blood creatinine. The longer and lower it goes, the higher the stage:
| KDIGO stage | Urine output criterion |
|---|---|
| Stage 1 | Under 0.5 ml/kg an hour for 6 to 12 hours |
| Stage 2 | Under 0.5 ml/kg an hour for 12 hours or more |
| Stage 3 | Under 0.3 ml/kg an hour for 24 hours or more, or no urine for 12 hours or more |
Newer KDIGO criteria from 2026 propose adding blood and biomarker tests to the definition; the urine output criterion is unchanged.
At home the same line means much less on its own. Output can dip below it for a few hours overnight or after a long stretch without drinking, with nothing wrong with the kidneys. Low output with little to drink is a fluid question. Low output despite normal drinking, or together with swelling, confusion or breathlessness, is a medical one.
Low and high output across a whole day
- Oliguria: under about 400 to 500 ml in 24 hours, roughly 20 ml an hour.
- Normal: about 1,200 to 2,000 ml in 24 hours for most adults.
- Polyuria: more than about 40 ml per kilogram in 24 hours, around 2,800 ml at 70 kg. Averaged over the day, that is about 1.7 ml/kg an hour. Drinking a lot is the most common cause.
These figures are for adults. Children's thresholds are different, so ask a paediatrician about a child's output.
See your own output, hour by hour
Bladder Journal records the time and volume of every void, adds up your 24-hour output and the night-time share, and shows how they change across weeks. Volume estimation from sound runs entirely on your device. Unlimited logging is free.
Download Bladder Journal freeSources: KDIGO Clinical Practice Guideline for Acute Kidney Injury, Kidney Int Suppl 2012;2:1-138 (definition and Table 2, staging); Goyal A, Daneshpajouhnejad P, Bashir K, Acute Kidney Injury, StatPearls, updated August 2026 (2026 KDIGO criteria).
This article is educational and does not provide medical advice, diagnosis or treatment.