Bladder diary, voiding diary or frequency–volume chart: what's the difference?

2 November 2026· 4 min read

The cover page of a printable bladder diary and a folded booklet version of the same diary

In short

A bladder diary, a voiding diary and a frequency–volume chart are, for the person filling them in, the same sheet. By the International Continence Society definitions a frequency–volume chart records the time and volume of every trip, a bladder diary adds drinks, leaks and pads, and a micturition time chart records times only; voiding diary, urinary diary, bladder chart and input/output chart are the same thing under other names. The form you were given is the one to use:

A frequency–volume chart records the time and volume of every trip. A bladder diary is the same plus drinks, leaks and pads. A micturition time chart records times only.
Voiding diary, urinary diary, bladder chart and input/output chart are the same thing under other names. The form you were given is the one to use.
Whatever the label, the columns are what matter: time, drink, volume passed, night, and a note.

By Denis Zinin, developer of Bladder Diary: Fluid Balance. Not a doctor.

You were told to keep a bladder diary. The leaflet says frequency–volume chart. The website you found says voiding diary or voiding log, and the nurse on the ward called it an input/output chart. They are, for your purposes, the same sheet. The differences that do exist are small, defined, and explained below, so that you can stop worrying about the label and get on with the columns.

The short version

Term	What it records	Who tends to say it
Micturition time chart	Only the time of each trip, day and night	Research, some clinics
Frequency–volume chart (FVC)	Time and volume of each trip	UK urology, NHS forms, BAUS
Bladder diary	Times and volumes plus drinks, leaks, pads, urgency	UK and international guidelines, NICE
Voiding diary, urinary diary, micturition diary	Same as bladder diary	US clinics and literature
Bladder record chart, bladder chart	Same as bladder diary	Physiotherapy services
Input/output chart, fluid balance chart	Drinks and urine over 24 hours; in hospital also drips and other losses	Wards and nursing; BAUS uses the name for its FVC

What is the difference between a bladder diary and a frequency–volume chart?

The International Continence Society, which sets the terminology urologists use, describes three levels of record.^1,3 A micturition time chart notes only the times of trips, day and night, for at least 24 hours. A frequency–volume chart adds the volume of each trip. A bladder diary adds fluid intake, pad use, incontinence episodes and the degree of incontinence, and may also record urgency and the activities that went with a leak.^1,2,3 Each level answers more questions than the one before, and the bladder diary is the one most guidelines mean when they ask for “a diary”: NICE, for example, asks women presenting with urinary incontinence to complete a bladder diary for at least three days.¹⁰

Why there are so many names

Partly geography, partly history. A review of the research literature had to search for nine different terms to find the same kind of record: micturition chart, micturition diary, frequency volume chart, bladder chart, bladder diary, urinary chart, urinary diary, voiding chart and voiding diary.⁴ American forms tend to say voiding or bladder diary; the Urology Care Foundation’s patient form is simply “Bladder Diary”.⁷ British forms often keep the older clinical name even when they are full diaries: the NHS Gloucestershire chart is headed “Frequency Volume Chart, Three Day Bladder Diary” and has columns for drinks, urine, bladder sensation and pads,⁵ and the BAUS leaflet explains its input/output chart as “also known as a frequency-volume chart or bladder diary”.⁶ Physiotherapy services have their own variant, the bladder record chart, with the same content.⁸

Input/output charts and fluid balance charts

These two names come from the ward. A fluid balance chart is a nursing record of everything that goes into a patient and everything that comes out, including drips, drains and vomit, used to manage fluids in hospital.⁹ When a nurse sends you home to “keep an input and output chart” after surgery or with a catheter, they usually mean the simple version: what you drank, what you passed, with times. That is a frequency–volume chart with a drinks column, which is why BAUS can use the name for its urology leaflet.⁶ The columns on our printable template cover it.

The same thing in other languages

If you keep the diary in another language, the term changes but the sheet does not: Blasentagebuch or Miktionsprotokoll in German, calendrier mictionnel in French, diario miccional in Spanish, diario minzionale in Italian, 排尿日誌 in Japanese. The app runs in the same languages as this site and prints the report in the language you choose, so a German urologist gets German column headings.

What this means for you

Use the form you were given. If your clinic said “frequency–volume chart” and handed you a sheet with a drinks column, fill in the drinks. If it said “bladder diary” and the sheet has columns for urgency and leaks, use them. If it gave you nothing and said “keep a diary”, any form with time, drink, volume passed, night and a note will do; that is what the template and the app both use, so a paper diary and an app diary read the same way. The label on top has never been the problem. The blank lines are.

Need a paper version?

A free printable bladder diary with the same columns: A4 or US Letter, full pages or fold-in-half booklets. No email, no sign-up.

Free PDF templates

Questions

Is a voiding diary the same as a bladder diary?

In practice, yes. "Voiding diary" is the usual American term and "bladder diary" the usual British one; the research literature uses both, along with urinary diary, micturition diary and bladder chart.⁴ If a form has columns for drinks and for urine with times, it is a bladder diary whatever its heading.

My clinic said frequency–volume chart. Do I still record drinks?

Strictly, a frequency–volume chart records only the times and volumes of urine passed.^1,3 Most clinic charts with that name also ask for drinks, as the NHS Gloucestershire chart and the BAUS chart do.^5,6 Follow the form: if it has a drinks column, fill it in; if it doesn't, recording drinks on a separate line never hurts.

What is a micturition time chart?

The simplest of the three: only the time of each trip, day and night, for at least 24 hours.^1,3 No volumes, no drinks. It answers the question "how often" and nothing else, which is sometimes all a clinician needs.

References

Abrams P, Cardozo L, Fall M, et al. The standardisation of terminology of lower urinary tract function: report from the Standardisation Sub-committee of the International Continence Society. Neurourol Urodyn. 2002;21(2):167–178. doi:10.1002/nau.10052
Haylen BT, de Ridder D, Freeman RM, et al. An International Urogynecological Association (IUGA)/International Continence Society (ICS) joint report on the terminology for female pelvic floor dysfunction. Neurourol Urodyn. 2010;29(1):4–20. doi:10.1002/nau.20798
International Continence Society. Bladder diary / frequency volume chart. ICS terminology discussion, Standardisation Steering Committee. ics.org
Bright E, Drake MJ, Abrams P. Urinary diaries: evidence for the development and validation of diary content, format, and duration. Neurourol Urodyn. 2011;30(3):348–352. doi:10.1002/nau.20994
Gloucestershire Hospitals NHS Foundation Trust. Frequency volume chart: three day bladder diary. Patient information leaflet GHNHSFT/X941/05_16. gloshospitals.nhs.uk (PDF)
British Association of Urological Surgeons. Information from BAUS about assessing fluid intake & output. Patient leaflet F24/016. BAUS; 2024. baus.org.uk (PDF)
Urology Care Foundation. Overactive bladder diary. Linthicum, MD: American Urological Association; 2025. urologyhealth.org (PDF)
University Hospitals Sussex NHS Foundation Trust. Bladder record chart: pelvic health physiotherapy patient information. Reference 2198; 2023. uhsussex.nhs.uk (PDF)
Scales K, Pilsworth J. The importance of fluid balance in clinical practice. Nurs Stand. 2008;22(47):50–57. doi:10.7748/ns2008.07.22.47.50.c6634
National Institute for Health and Care Excellence. Urinary incontinence and pelvic organ prolapse in women: management. NICE guideline NG123. London: NICE; 2019. nice.org.uk

This article explains how to keep a diary. It is general information from an app developer, not medical advice: your clinician decides what your diary means. Self-reported diary. Not a medical document.

Keep the diary on your phone

Two taps per entry, totals done for you, a PDF report at the end. No account, no server, nothing leaves your phone.