Calzyra
CalzyraCALCULATE | CONVERT | SOLVE
FinanceInvestmentsHealthMathBlog
Calzyra
CalzyraCALCULATE | CONVERT | SOLVE

Smart calculators for every need. Trusted by millions of users worldwide for accurate, fast, and free calculation tools.

Popular Categories

  • Finance
  • Health & Fitness
  • Mathematics
  • Physics
  • Construction
  • Conversion

Finance Tools

  • Loan Calculators
  • Investment Calculators
  • Compound Interest
  • SIP Calculator
  • ROI Calculator
  • CAGR Calculator

Top Calculators

  • Mortgage Calculator
  • BMI Calculator
  • Percentage Calculator
  • Calorie Calculator
  • Tip Calculator

Company

  • About Us
  • Blog
  • Contact
  • Privacy Policy
  • Terms of Service

© 2026 Calzyra. All rights reserved.

Trusted by 2M+ monthly users
  1. Home
  2. Health
  3. Hydration
  4. Rehydration Calculator
Medical CalculatorHydration

Rehydration Calculator

Calculate how much fluid you need to drink to recover from dehydration based on weight lost.

Updated 2024-12-152 min readCalzyra Health Team

Calculator

Enter your values below

Health CalculatorEvidence-Based

Your typical well-hydrated weight.

Based on percentage of body weight lost.

Formula & Methodology

How this calculator works

Fluid needed = Weight lost × 1.5 (includes ongoing losses)

To rehydrate, drink 1.5 times the fluid you lost. For example, if you lost 1 kg (1 liter), drink 1.5 liters over 2-4 hours. Severe dehydration (>3% body weight loss) requires medical attention.

Frequently Asked Questions

Common questions about this calculator

Medical Disclaimer

Hydration needs vary based on health conditions, medications, and activity levels. Consult a healthcare provider if you have fluid restriction requirements.

Hydration Calculators

Water Intake CalculatorDehydration Risk CalculatorSports Drink CalculatorElectrolyte CalculatorHydration Status CalculatorPre-Hydration CalculatorRehydration CalculatorDaily Fluid Calculator

Related Calculators

Water Intake Calculator

Find your recommended daily water intake.

Quick Links

All Health CalculatorsHydration Category

References

WHO GuidelinesCDC ResourcesAHA Recommendations