Azure Reserved VM Savings Calculator

Test whether a reserved VM instance pays off at your real utilisation, and find the break-even usage point.

Inputs

Pay-as-you-go rateUSD/hour

Instances to reserveinstances

Reservation term

1-year reserved rateUSD/hour

3-year reserved rateUSD/hour

Hours the instances actually run%

A reservation bills all 730 hours whether the VM runs or not.

Billed hours per monthhours

Monthly Saving

$543.41

Saving vs Actual Usage

47.3%

Break-even Utilisation

43.2%

Reservation Charge

$605.90

Pay-as-you-go Cost of the Same Usage

$1,149.31

Saving Over the Whole Term

$19,562.83

Recommendation

Reservation pays off comfortably at this utilisation

Step by step

Values used
Pay-as-you-go rate = 0.1920 USD/hour; Instances to reserve = 10 instances; Reservation term = 3-year term; 1-year reserved rate = 0.1210 USD/hour; 3-year reserved rate = 0.0830 USD/hour; Hours the instances actually run = 82 %; Billed hours per month = 730 hours
Azure Reserved VM Savings
reservation cost = instances × reserved rate × 730 (billed in full); pay-as-you-go cost = instances × rate × 730 × utilisation; break-even utilisation = reserved rate ÷ pay-as-you-go rate.
Monthly Saving
= 543.41
Saving vs Actual Usage
= 47.3
Break-even Utilisation
= 43.2
Reservation Charge
= 605.90
Pay-as-you-go Cost of the Same Usage
= 1,149.31
Saving Over the Whole Term
= 19,562.83

How it works

A reservation bills the full 730 hours per month for the whole term whether the VM runs or not, so the break-even point is simply the ratio of the reserved rate to the pay-as-you-go rate — around 43% for a 3-year term. Below that utilisation the reservation loses money; above it the saving grows linearly with usage. Reservations are the single largest Azure discount available without renegotiating an agreement, but they are the wrong instrument for bursty or seasonal workloads — a savings plan or Spot capacity fits those better. Confirm both the pay-as-you-go and reserved rates for your size and region in the Azure pricing calculator.

Formula

Azure Reserved VM Savings

reservation cost = instances × reserved rate × 730 (billed in full); pay-as-you-go cost = instances × rate × 730 × utilisation; break-even utilisation = reserved rate ÷ pay-as-you-go rate.

break-even utilisation: Fraction of the month a VM must run before the reservation is cheaper
utilisation: Share of the 730 hours the instances are actually running
term saving: Monthly saving extended across the whole 12 or 36 months

Frequently Asked Questions

How is Azure Reserved VM Savings calculated?

reservation cost = instances × reserved rate × 730 (billed in full); pay-as-you-go cost = instances × rate × 730 × utilisation; break-even utilisation = reserved rate ÷ pay-as-you-go rate. A reservation bills the full 730 hours per month for the whole term whether the VM runs or not, so the break-even point is simply the ratio of the reserved rate to the pay-as-you-go rate — around 43% for a 3-year term. Below that utilisation the reservation loses money; above it the saving grows linearly with usage.

Why does Azure Reserved VM Savings matter?

Reservations are the single largest Azure discount available without renegotiating an agreement, but they are the wrong instrument for bursty or seasonal workloads — a savings plan or Spot capacity fits those better. Confirm both the pay-as-you-go and reserved rates for your size and region in the Azure pricing calculator.

What values do I need to enter?

This calculator takes 7 inputs: Pay-as-you-go rate, Instances to reserve, Reservation term, 1-year reserved rate, 3-year reserved rate, Hours the instances actually run, Billed hours per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

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