Patient Information
Validated range: 18 to 100 years.
Sex
Used in both the KFRE and CKD-EPI equations.
Region (calibration)
Sets the region-specific baseline survival values.
Kidney Function & Albuminuria
How do you want to provide eGFR?
Creatinine mode uses the CKD-EPI (2009) equation.
The KFRE is validated for eGFR below 60.
1 mg/mmol = 8.84 mg/g.
Extended Laboratory Values (8-variable model)
Do you have values for Albumin, Phosphorous, Bicarbonate and Corrected Calcium?

Your Inputs

Kidney Failure Risk

CKD Stage (GFR Category)

Chronic kidney disease stage based on the patient's eGFR. The patient's current stage is highlighted.
GFR category eGFR (mL/min/1.73m2) Description Patient

KDIGO Risk Classification Grid

Scroll horizontally to see all albuminuria categories on small screens.

KDIGO risk of adverse kidney outcomes by GFR category (rows) and albuminuria category (columns). Each cell states its risk tier in text; the patient's cell is outlined and marked "You".
GFR category (eGFR range) A1
< 30 mg/g
< 3 mg/mmol
A2
30–299 mg/g
3–29 mg/mmol
A3
≥ 300 mg/g
≥ 30 mg/mmol

Clinical Decision Thresholds — How Your Results Compare

Step-by-Step Solution


Introduction

The Kidney Failure Risk Equation (KFRE) Calculator shows the chance that a person with chronic kidney disease (CKD) will need dialysis or a kidney transplant in the next 2 or 5 years. It uses the equation built by Tangri and colleagues, which has been tested in 721,357 people in North America and other regions.1

To get a result, enter four things: age, sex, eGFR, and urine albumin-to-creatinine ratio (UACR). If you also have lab values for albumin, phosphorous, bicarbonate, and calcium, the tool uses the 8-variable model, which is more exact. Don't have an eGFR number? Enter serum creatinine instead, and the calculator works it out with the CKD-EPI equation.

This tool is for adults with CKD who have an eGFR under 60 mL/min/1.73m². Along with your risk percent, you get your KDIGO stage, your spot on the KDIGO risk grid, how your numbers compare to common care thresholds (like when to see a kidney specialist), and a step-by-step solution that shows the full math.

Results are an estimate, not a diagnosis. Always talk with your doctor or kidney care team about what your numbers mean for you.

How to use our Kidney Failure Risk Equation (KFRE) Calculator

Enter a few patient details and lab values, and this KFRE calculator shows the 2-year and 5-year risk of kidney failure, the CKD stage, and the KDIGO risk category.

Age (years): Type the patient's age. It must be between 18 and 100.

Sex: Pick Female or Male. This is used in both the KFRE and the eGFR equations.

Region: Choose North America or Non-North America. This sets the right baseline values for the risk math.

eGFR input choice: Pick "I have an eGFR value" if you already know it. Pick "Calculate from creatinine" and the tool will work it out using the CKD-EPI 2009 equation.

eGFR (mL/min/1.73m²): Type the eGFR value. The KFRE works best for values under 60.3

Serum creatinine: Only shows if you chose the creatinine option. Type the lab value and pick mg/dL or µmol/L. Changing the unit converts the number for you.

Urine albumin:creatinine ratio (UACR): Type the urine test result and pick mg/g or mg/mmol. This shows how much protein leaks into the urine.

Extra lab values (yes or no): Choose Yes to use the more exact 8-variable KFRE model. Choose No to use the shorter 4-variable model.

Serum albumin: Type the blood albumin level in g/dL or g/L.

Phosphorous: Type the blood phosphorous level in mg/dL or mmol/L.

Bicarbonate: Type the blood bicarbonate level in mEq/L or mmol/L.

Corrected calcium: Type the corrected blood calcium level in mg/dL or mmol/L.

Calculate and Reset: Click Calculate to see the results, or Reset to clear everything and start over.

What Is the Kidney Failure Risk Equation (KFRE)?

The Kidney Failure Risk Equation, or KFRE, predicts the chance that a person with chronic kidney disease (CKD) will need dialysis or a kidney transplant. It gives that chance as a percent over the next 2 years and the next 5 years. Dr. Tangri and colleagues built it in 2011.2 It has since been tested in 721,357 people.1 KDIGO recommends using a validated risk equation like this one for people with CKD stages G3 to G5.3

What the KFRE Uses

The basic KFRE uses four things:

  • Age, in years.
  • Sex, male or female.
  • eGFR, how well your kidneys filter blood. Lower numbers mean worse kidney function.
  • UACR, how much albumin (a protein) leaks into your urine. Higher numbers mean more kidney damage.

An 8-variable version adds four blood tests: albumin, phosphorous, bicarbonate, and corrected calcium. These extra labs make the answer a bit more exact, but the 4-variable version still works very well on its own.

Why Region Matters

Kidney failure rates are not the same everywhere. The KFRE uses different baseline numbers for North America and for the rest of the world.1 Picking the right region gives a more correct risk.

What the Risk Numbers Mean

The result is a percent chance of kidney failure. For example, a 12% 5-year risk means about 12 out of 100 people just like you would need dialysis or a transplant within 5 years. Most people with CKD never reach kidney failure, so a low number is common and is good news. Care teams often use these cut points:

  • 3% to 5% or more over 5 years: see a kidney doctor (nephrologist).3
  • More than 10% over 2 years: get team care with a nurse, dietitian, and pharmacist.3
  • 20% to 40% or more over 2 years: start planning for dialysis access or a transplant.3

CKD Stages and the KDIGO Grid

KDIGO is a group that sets kidney care guidelines. It sorts CKD by eGFR (stages G1 to G5) and by urine albumin (A1, A2, A3).3 Putting the two together gives a risk color: low, moderate, high, or very high.3 A person can have a fair eGFR but still be high risk if a lot of albumin leaks into the urine.3

Treatments That Lower Risk

Kidney risk is not fixed. Proven treatments can slow CKD down:

  • Blood pressure control, keeping pressure in a safe range.3
  • SGLT2 inhibitors, pills that protect kidneys. KDIGO recommends them when eGFR is 20 or higher.3
  • RAAS inhibitors, ACE inhibitors or ARBs that cut protein loss in urine.3
  • Finerenone, for people with type 2 diabetes and CKD.3

Diet changes, quitting smoking, and treating diabetes also help.3

Who It Is For and Its Limits

The KFRE is made for adults with CKD stages G3 to G5, meaning an eGFR under 60.3 It is not built for people who already have kidney failure, for children, or for sudden (acute) kidney injury. It predicts kidney failure only, not heart disease or death. The score is an estimate based on large groups of people, not a promise about one person. Always go over your results with a doctor.


Formulas used

4-variable KFRE risk score (X) 1
X_{4} = -0.2201\left(\frac{\text{Age}}{10} - 7.036\right) + 0.2467\left(\text{Sex} - 0.5642\right) - 0.5567\left(\frac{\text{eGFR}}{5} - 7.222\right) + 0.4510\left(\ln(\text{UACR}) - 5.137\right)
8-variable KFRE risk score (X) 1
X_{8} = -0.1992\left(\frac{\text{Age}}{10} - 7.036\right) + 0.1602\left(\text{Sex} - 0.5642\right) - 0.4919\left(\frac{\text{eGFR}}{5} - 7.222\right) + 0.3364\left(\ln(\text{UACR}) - 5.137\right) - 0.3441\left(\text{Alb} - 3.997\right) + 0.2604\left(\text{Phos} - 3.916\right) - 0.07354\left(\text{HCO}_3 - 25.57\right) - 0.2228\left(\text{Ca} - 9.355\right)
Kidney failure risk at 2 and 5 years 1
R_{t} = 1 - \left(S_{0,t}\right)^{e^{X}}
Baseline survival constants (North America / non-North America) 1
\begin{array}{lcc} \text{4-var, NA:} & S_{0,2}=0.9750 & S_{0,5}=0.9240 \\ \text{4-var, non-NA:} & S_{0,2}=0.9832 & S_{0,5}=0.9365 \\ \text{8-var, NA:} & S_{0,2}=0.9780 & S_{0,5}=0.9301 \\ \text{8-var, non-NA:} & S_{0,2}=0.9827 & S_{0,5}=0.9245 \end{array}
eGFR from serum creatinine (CKD-EPI 2009) 4
\text{eGFR} = 141 \times \min\left(\frac{S_{cr}}{\kappa},1\right)^{\alpha} \times \max\left(\frac{S_{cr}}{\kappa},1\right)^{-1.209} \times 0.993^{\text{Age}} \times 1.018_{\text{[if female]}}, \quad \kappa = \begin{cases} 0.7 & \text{female} \\ 0.9 & \text{male} \end{cases}, \quad \alpha = \begin{cases} -0.329 & \text{female} \\ -0.411 & \text{male} \end{cases}
Unit conversions to canonical units
\begin{aligned} S_{cr}[\text{mg/dL}] &= \frac{S_{cr}[\mu\text{mol/L}]}{88.4} & \text{UACR}[\text{mg/g}] &= \text{UACR}[\text{mg/mmol}] \times 8.84 \\ \text{Alb}[\text{g/dL}] &= \text{Alb}[\text{g/L}] \times 0.1 & \text{Phos}[\text{mg/dL}] &= \text{Phos}[\text{mmol/L}] \times 3.09717 \\ \text{Ca}[\text{mg/dL}] &= \text{Ca}[\text{mmol/L}] \times 4.00802 \end{aligned}

Frequently asked questions

What is a normal UACR level?

A urine albumin-to-creatinine ratio (UACR) under 30 mg/g (under 3 mg/mmol) is normal.3 Higher numbers mean albumin is leaking into your urine, which is a sign of kidney damage.3

  • A1: under 30 mg/g, normal to mildly increased
  • A2: 30 to 299 mg/g, moderately increased
  • A3: 300 mg/g or more, severely increased3

UACR is a strong warning sign. Two people can have the same eGFR, but the one with a higher UACR has a higher chance of kidney failure.3

How is a UACR test done?

You pee into a cup, and the lab measures two things in that one sample: albumin and creatinine. Dividing one by the other gives the ratio. You do not need to collect urine for 24 hours.

A first-morning, midstream sample is preferred.3 Exercise, a urine infection, your period or blood in the urine can raise the number.3 Because of this, a random result of 30 mg/g or more is confirmed with a first-morning sample.3

At what eGFR do you need dialysis?

There is no single number. Dialysis is started because of symptoms and lab results, and this often happens when eGFR is between 5 and 10.3 Planning for dialysis or a transplant starts earlier, when eGFR falls below about 15 to 20 or the 2-year risk of kidney failure is above 40%.3

Symptoms matter more than the number alone. Signs it may be time include loss of appetite, itching, confusion, fluid or blood pressure that cannot be controlled, and high potassium or acid levels that medicine cannot fix.3

Does a high KFRE score mean I will definitely need dialysis?

No. The score is a chance, not a promise. A 5-year risk of 30% means about 30 out of 100 similar people reach kidney failure in 5 years. The other 70 do not.

The score also assumes nothing changes. Starting treatments like SGLT2 inhibitors, ACE inhibitors or ARBs, and better blood pressure control can slow kidney disease and lower that risk.3 A high score is a reason to act early, not a reason to give up.

How fast does chronic kidney disease get worse?

It depends on the person. eGFR goes down slowly with age, even in people without kidney disease.6 Many people with stable CKD never reach kidney failure.

CKD moves faster when there is a lot of albumin in the urine, uncontrolled diabetes, high blood pressure, or repeated kidney injuries. At the same eGFR, more albumin in the urine means a higher risk of getting worse.3

Can chronic kidney disease be reversed?

Scarred kidney tissue does not grow back, so CKD usually cannot be reversed. But it can often be slowed down a lot, and sometimes eGFR goes up a little once blood pressure, blood sugar, and urine protein are under control.

The biggest wins are controlling blood pressure, taking an ACE inhibitor or ARB, adding an SGLT2 inhibitor, cutting salt, quitting smoking, and avoiding NSAID pain pills like ibuprofen.3

Why do doctors check phosphorus, bicarbonate, and calcium in kidney disease?

Damaged kidneys stop balancing minerals and acid in the blood. These four labs show how much that balance has slipped:

  • Phosphorus builds up when kidneys cannot clear it. High levels harm bones and blood vessels.
  • Bicarbonate drops when acid builds up. Low levels speed up kidney loss and weaken muscle.
  • Calcium falls out of balance with phosphorus and vitamin D.
  • Albumin drops with poor nutrition or heavy protein loss in urine.

Abnormal values point to more advanced disease, which is why the 8-variable KFRE is a bit sharper than the 4-variable one.

What is the difference between the 2009 and 2021 CKD-EPI eGFR equations?

The 2009 CKD-EPI equation included a race factor that raised eGFR for Black patients.4 The 2021 version was refitted without it; race is a social label, not a biological measure of kidney function.5

Without the race factor, the 2021 equation slightly overestimates kidney function in non-Black people and slightly underestimates it in Black people.3 A national task force recommended in 2021 that all US labs switch to it.5 This calculator uses the 2009 equation when it works out eGFR from creatinine.

Why does a younger person have a higher kidney failure risk than an older person with the same eGFR?

Because younger people have more years for the disease to progress, and a low eGFR at a young age usually means a more aggressive disease.

In older adults, a mildly low eGFR is often just normal aging. They are also more likely to die of something else, like heart disease, before their kidneys fail. That is why age lowers the KFRE score, even though older people are more likely to have CKD.

How often should eGFR and UACR be checked in CKD?

At least once a year for everyone with CKD, and more often at higher risk. The KDIGO guideline suggests from once a year at the lowest-risk stages up to four or more times a year at the highest.3

Always check both tests together.3 eGFR alone misses people who have heavy protein loss but decent filtering.

Does drinking more water lower creatinine or improve eGFR?

Not really. Drinking extra water does not repair kidneys or raise eGFR in any lasting way, and it has not been shown to slow kidney loss in people with CKD.

What does matter is not getting dehydrated. Being very dry raises creatinine and drops eGFR for a short time, so a lab drawn while you are dehydrated can look worse than your true level.7 Drink when thirsty unless your doctor limits your fluids.

What is the difference between chronic kidney disease and kidney failure?

Chronic kidney disease means your kidneys are damaged or filtering less well for at least 3 months.3 Most people with early CKD have no symptoms.6

Kidney failure, also called end-stage kidney disease, means the kidneys have stopped working well enough to keep you alive without help. At that point a person needs dialysis or a transplant. This is the exact event the KFRE predicts.

What diet changes help slow kidney disease?

A few simple changes help most people with CKD:

  • Cut sodium to under 2 grams a day.3 This helps lower blood pressure.
  • Skip phosphate additives in processed food, soda, and deli meat. Look for ingredients with "phos" in the name.
  • Eat less animal protein and more plants, beans, fruit, and vegetables.3
  • Limit potassium only if your blood potassium is high. Not everyone needs to.

Ask for a kidney dietitian. Food rules change as CKD advances, so general advice may not fit your stage.


Sources

  1. Tangri N, Grams ME, Levey AS, Coresh J, Appel LJ, Astor BC, et al. Multinational assessment of accuracy of equations for predicting risk of kidney failure: a meta-analysis. JAMA. 2016;315(2):164-174; Supplement, eAppendix 2. doi:10.1001/jama.2015.18202. Accessed September 26, 2026.
  2. Tangri N, Stevens LA, Griffith J, Tighiouart H, Djurdjev O, Naimark D, et al. A predictive model for progression of chronic kidney disease to kidney failure. JAMA. 2011;305(15):1553-1559. doi:10.1001/jama.2011.451. Accessed September 26, 2026.
  3. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney International. 2024;105(4S):S117-S314. doi:10.1016/j.kint.2023.10.018. Accessed September 26, 2026.
  4. Levey AS, Stevens LA, Schmid CH, Zhang YL, Castro AF 3rd, Feldman HI, et al. A new equation to estimate glomerular filtration rate. Annals of Internal Medicine. 2009;150(9):604-612. doi:10.7326/0003-4819-150-9-200905050-00006. Accessed September 26, 2026.
  5. Delgado C, Baweja M, Crews DC, Eneanya ND, Gadegbeku CA, Inker LA, et al. A unifying approach for GFR estimation: recommendations of the NKF-ASN Task Force on reassessing the inclusion of race in diagnosing kidney disease. Journal of the American Society of Nephrology. 2021;32(12):2994-3015. doi:10.1681/ASN.2021070988. Accessed September 26, 2026.
  6. Estimated GFR (eGFR) Test: Kidney Function Levels, Stages, and What to Do Next. National Kidney Foundation. Accessed September 26, 2026.
  7. Creatinine blood test. MedlinePlus, U.S. National Library of Medicine. Accessed September 26, 2026.