How do you calculate carboplatin dose using the Calvert formula?

The Calvert formula calculates carboplatin dose as: Dose (mg) = Target AUC × (GFR + 25). The target AUC is determined by the treatment protocol (typically AUC 5–7 for first-line regimens), and GFR is either measured directly (e.g., nuclear medicine scan) or estimated via creatinine clearance using the Cockcroft-Gault equation. The constant 25 accounts for nonrenal carboplatin clearance.

What target AUC should be used for carboplatin?

Target AUC depends on the cancer type and regimen. Common targets: AUC 5 for ovarian cancer (combination therapy with paclitaxel), AUC 5–6 for non-small cell lung cancer (with pemetrexed or paclitaxel), AUC 6 for ovarian cancer (single agent or combination), AUC 2 for weekly low-dose regimens, and AUC 7 for some high-dose protocols. Always follow the specific protocol being used.

Why should GFR be capped at 125 mL/min for carboplatin dosing?

The FDA recommends capping GFR at 125 mL/min when using estimated GFR (not measured) to prevent carboplatin overdosing. This recommendation was issued in 2010 after reports of toxicity when IDMS-calibrated creatinine assays produced lower creatinine values, leading to higher calculated GFR and thus higher carboplatin doses. The cap applies when using Cockcroft-Gault or Jelliffe equations with IDMS creatinine.

What is the maximum dose of carboplatin?

There is no absolute maximum dose, but the FDA GFR cap at 125 mL/min effectively limits the dose. For AUC 6, this means a maximum of approximately 900 mg [6 × (125 + 25)]. Some institutions set protocol-specific maximum doses. Actual doses should be verified against institutional guidelines and the specific treatment protocol.

Should actual or ideal body weight be used for carboplatin dosing?

When using Cockcroft-Gault to estimate CrCl for the Calvert formula, weight selection matters. The original Cockcroft-Gault used actual body weight. For obese patients (>120% of ideal body weight), some practitioners use adjusted body weight [IBW + 0.4 × (actual − IBW)] to avoid overestimating CrCl and thus carboplatin dose. There is no universal consensus, but using actual weight in obesity can lead to overdosing.

Back to all tools

Home / Carboplatin dose

Carboplatin Dose Calculator (Calvert Formula)

Calculate carboplatin dose in mg using the Calvert formula: Dose = Target AUC × (GFR + 25). Supports measured GFR or estimated CrCl via Cockcroft–Gault.

Inputs

Target AUC (mg·min/mL) Select per treatment protocol. Most common: AUC 5–6.

GFR method

Measured GFR (mL/min) From nuclear medicine (⁵¹Cr-EDTA, ⁹⁹ᵐTc-DTPA) or iohexol clearance.

Sex

Age (years)

Weight

Actual body weight. See notes on obesity below.

Serum creatinine Units: mg/dL

Creatinine units

Cap GFR at 125 mL/min (FDA recommendation) Recommended when using estimated GFR to prevent overdosing with IDMS creatinine assays.

BSA (m²) — optional If provided, dose per m² will also be displayed.

—

Enter inputs to calculate carboplatin dose.

Disclaimer: For educational purposes only. Not a substitute for clinical judgment. Always verify carboplatin dosing against your institutional protocol and pharmacy review.

Clinical pearls

Calvert formula: Dose (mg) = AUC × (GFR + 25). The constant 25 represents average nonrenal carboplatin clearance.
FDA GFR cap: In 2010, the FDA recommended capping GFR at 125 mL/min when using estimated (not measured) GFR, after reports of overdosing due to IDMS-standardized creatinine assays yielding lower creatinine values.
Obesity: Using actual body weight in obese patients overestimates CrCl. Consider adjusted body weight: AdjBW = IBW + 0.4 × (actual − IBW). No universal consensus exists.
Minimum creatinine: Some protocols round low creatinine values up to 0.7 mg/dL to prevent overestimation of CrCl in cachectic patients.
Renal monitoring: Check serum creatinine and electrolytes before each cycle. Carboplatin is nephrotoxic; dose-reduce for declining GFR.
Hydration: Adequate hydration is recommended but aggressive hydration (as with cisplatin) is typically not required.

Common regimens

TCPaclitaxel + Carboplatin AUC 5–6 q3w

GemCarboGemcitabine + Carboplatin AUC 5 q3w

Carbo/PemetrexedCarboplatin AUC 5 + pemetrexed q3w

Carbo/EtoposideCarboplatin AUC 5–6 + etoposide (SCLC)

CarboPac (Gyn)Carboplatin AUC 5–7.5 + paclitaxel (ovarian)

Weekly CarboCarboplatin AUC 2 weekly (radiosensitizer)

References

Calvert AH, Newell DR, Gumbrell LA, et al. Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin Oncol. 1989;7(11):1748–1756.
FDA Drug Safety Communication. Carboplatin dosing, 2010. Available at: fda.gov.
NCCN Clinical Practice Guidelines in Oncology: Non-Small Cell Lung Cancer, Ovarian Cancer. National Comprehensive Cancer Network, 2024.
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31–41.

Related tools

About This Tool

What Is the Calvert Formula?

The Calvert formula, published in 1989 by Calvert et al. in the Journal of Clinical Oncology, is the standard method for calculating carboplatin doses in oncology. Unlike most cytotoxic agents dosed per body surface area (mg/m²), carboplatin is dosed based on target area under the concentration-time curve (AUC) and renal function. The formula is: Dose (mg) = Target AUC × (GFR + 25), where GFR is in mL/min and 25 represents average nonrenal clearance of carboplatin.

Why AUC-Based Dosing?

Carboplatin clearance is primarily renal, correlating closely with GFR. By targeting a specific AUC rather than using a fixed mg/m² dose, the Calvert formula accounts for individual variation in renal function. This approach reduces the risk of both underdosing (subtherapeutic AUC) in patients with good renal function and overdosing (excess toxicity, particularly thrombocytopenia) in patients with impaired renal function. AUC-based dosing has been shown to produce more predictable platelet nadirs compared with BSA-based dosing.

GFR Estimation: Measured vs. Estimated

The original Calvert formula was validated using measured GFR (⁵¹Cr-EDTA clearance). In clinical practice, measured GFR is often unavailable, so creatinine clearance estimated by the Cockcroft-Gault equation is commonly substituted. This is an approximation — CrCl overestimates true GFR due to tubular creatinine secretion. When using estimated CrCl, the FDA recommends capping GFR at 125 mL/min to prevent overdosing, particularly with IDMS-standardized creatinine assays that tend to yield lower creatinine values and thus higher calculated clearance.

The FDA GFR Cap at 125 mL/min

In 2010, the FDA issued a safety communication recommending that when using estimated GFR (Cockcroft-Gault or Jelliffe), clinicians should cap the GFR at no more than 125 mL/min for carboplatin dose calculations. This was prompted by reports of carboplatin overdoses after clinical laboratories switched to IDMS-traceable creatinine assays, which report lower creatinine values (approximately 10–20% lower) than older methods. Lower creatinine → higher estimated GFR → higher calculated carboplatin dose → increased toxicity risk. The cap does not apply when using measured GFR from nuclear medicine studies.

Body Weight Considerations

The Cockcroft-Gault equation uses body weight, raising the question of which weight to use in obese patients. Using actual body weight in obesity overestimates CrCl and can lead to carboplatin overdosing. Options include: (1) actual body weight (original CG validation), (2) ideal body weight (IBW), or (3) adjusted body weight [IBW + 0.4 × (actual − IBW)]. The ASCO/ONS guidelines and many institutions recommend adjusted body weight for patients >120% of IBW. Always follow your institutional protocol.

🔑 Clinical Pearls

The Calvert formula gives the dose in mg (not mg/m²). Do not multiply by BSA.
For patients with AKI or rapidly changing creatinine, estimated GFR is unreliable. Consider measured GFR or delay treatment until renal function stabilizes.
Some protocols set a minimum serum creatinine (e.g., 0.7 mg/dL) to prevent overestimation in patients with very low muscle mass.
Carboplatin-induced thrombocytopenia is dose-limiting. Nadir typically occurs at day 14–21, with recovery by day 28.
Dose modifications between cycles are usually based on nadir counts and renal function reassessment, not the Calvert formula alone.
When combining with paclitaxel (TC regimen), administer paclitaxel first to reduce myelosuppression.

Key References

Calvert AH, Newell DR, Gumbrell LA, et al. Carboplatin dosage: prospective evaluation of a simple formula based on renal function. J Clin Oncol. 1989;7(11):1748–1756.
FDA Drug Safety Communication: New recommendations to improve the safe use of the injectable drug carboplatin. U.S. Food and Drug Administration, 2010.
Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976;16(1):31–41.
NCCN Clinical Practice Guidelines in Oncology (various tumor sites). National Comprehensive Cancer Network, 2024.
Ekhart C, de Jonge ME, Huitema AD, et al. Flat dosing of carboplatin is justified in adult patients with normal renal function. Clin Cancer Res. 2006;12(21):6502–6508.

Formula last verified: February 2026