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Islamic

Fasting Duration Calculator

Use this fasting duration calculator to calculate calculate fasting duration from suhoor/fajr offset and iftar/maghrib offset.

fasting durationramadanhours

Calculator

Calculate instantly

Calculator Inputs

Choose what you want to calculate, enter realistic values, adjust units where shown, and use the scenario section for repeated-use planning.

Input and Formula Breakdown

This calculator applies the formula Duration = iftar time - start time. Enter each value with the matching unit, and AZCalculate updates the result instantly.

Fast start hour
4.5 hours
Fast end hour
18.8 hours
Fasting duration
14.3 hours

Scenario and Comparison

Current

14.3 hours

Projected

171.6

Adjusted

15.73

Visual Comparison

Current result14.3
Projected usage171.6
Comparison scenario15.73

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Trust note

Important estimate

This calculator is informational and should be verified before financial, health, legal, engineering, laboratory, or safety-critical decisions.

High risk contextDifficulty: advancedConfidence estimate: 87/100Reviewed 2026-05-18Reviewed by: Islamic content reviewerCalculator vuces-2.1 / Formula vformula-1.02 sources listed

Formula and Explanation

Duration = iftar time - start time

This calculator applies the formula Duration = iftar time - start time. Enter each value with the matching unit, and AZCalculate updates the result instantly.

Variable descriptions

startHour(hours)
Fast start hour: Fast start hour measured in hours, entered as a known value.
endHour(hours)
Fast end hour: Fast end hour measured in hours, entered as a known value.

Formula Notes

  • Use consistent units for values that are multiplied, divided, or compared.
  • Results may be rounded for readability, while the calculator keeps greater precision internally.
  • Real-world measurements and assumptions can introduce small differences from the calculated estimate.

Common uses

  • Estimate fasting hours
  • Compare days
  • Plan schedules

Assumptions

What this calculation assumes

  • The calculation follows the method shown on the page.
  • Local scholarly guidance and asset valuation dates can change interpretation.
  • Inputs are assumed to describe the same scenario and use compatible units.
  • Results may be rounded for readability.

Avoid mistakes

Quick checks before you rely on the result

  • Using outdated gold or silver values.
  • Ignoring liabilities, eligibility, methodology, or local scholarly guidance.
  • Mixing units, periods, currencies, or measurement systems without converting first.
  • Rounding intermediate values too early.

Step-by-Step Explanation

Follow the reasoning, not only the final number.

  1. 1

    Set up the calculation

    Enter the known values in the calculator fields.

    Starting with clearly defined values and units prevents the most common calculation errors.

  2. 2

    Work through step 2

    Keep the units consistent with the labels shown beside each input.

    This step transforms the known values into the form required by the formula.

  3. 3

    Work through step 3

    Apply the formula: Duration = iftar time - start time.

    This step transforms the known values into the form required by the formula.

  4. 4

    Interpret the result

    Review the primary result and supporting values.

    Compare the result with your real-world goal, such as estimate fasting hours.

Worked example

Practical fasting duration calculator example

Known values

  • Fast start hour: 4.5 hours
  • Fast end hour: 18.8 hours

Calculation

  1. 1. Start with the known values shown for this fasting duration calculator scenario.
  2. 2. Substitute those values into Duration = iftar time - start time.
  3. 3. Evaluate the expression and keep the requested unit and rounding.

Result and meaning

Fasting duration: 14.3 hours

Calculator guide

About this Fasting Duration Calculator

Calculate fasting duration from suhoor/fajr offset and iftar/maghrib offset. This page includes an interactive calculator, concise formula notes, worked examples, FAQs, related calculators, and practical guidance you can revisit whenever needed.

References

Sources used for this calculator

Found something that does not look right?

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Calculator usage

Usage information loads after the calculator is ready.

FAQ

Fasting Duration Calculator FAQs

How does the fasting duration calculator work?+

It uses Duration = iftar time - start time and calculates the result from the values you enter.

Can I copy or print the result?+

Yes. AZCalculate calculator pages include copy, share, and print actions.

Can methodology vary?+

Yes. Islamic calculation methods can vary by school, jurisdiction, and scholarly guidance.

Is this religious advice?+

No. It is an estimate and should be reviewed with qualified guidance for important decisions.

How should I use this calculator result?+

Use it as an estimate and compare it with the formula, assumptions, and examples shown on the page.

Why can real-world results differ?+

Real-world inputs can include local rules, changing rates, measurement tolerances, and conditions outside the core formula.

What information do I need for the fasting duration calculator?+

Enter the known values requested by the calculator. Use the unit selectors where available and make sure the values describe the same scenario.

How accurate is the fasting duration calculator?+

The calculator follows the formula shown on this page. Accuracy depends on the values, units, assumptions, and rounding used in your scenario.

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Fasting Duration Calculator - AZCalculate | AZCalculate