Compare the cost of useful, supported service
The shelf price leaves out the charger or dock that makes the device usable, storage and software needed each month, repairs and downtime, migration work and the value recovered at the end. A cheaper device can cost more per supported year.
Choose a realistic ownership period and add purchase, essential accessories, finance, connectivity, software, cloud storage, energy, repair, downtime and migration. Subtract credible resale or trade-in value, then divide by years of useful supported service and test an early-failure scenario.
Use one complete formula
Use the same period and assumptions for every option. If one device has only two credible supported years remaining and another has five, comparing their purchase prices alone does not measure the service being bought.
Find the costs that hide outside the product page
| Cost area | Phone questions | Computer questions |
|---|---|---|
| Ready to use | Charger, cable, case, screen protection, SIM or eSIM move and accessibility accessories. | Display, keyboard, mouse, dock, adapters, webcam, storage, bag and ergonomic setup. |
| Ongoing service | Mobile plan, insurance, cloud storage, application subscriptions and international use. | Operating-system edition, office or specialist software, security, cloud backup and internet. |
| Operation | Charging energy is usually small but battery replacement, charging time and unavailable service matter. | Energy use varies with form factor and workload; also include noise, cooling and any justified backup power. |
| Failure | Screen, battery, port, camera, lost-device excess, temporary replacement and authentication disruption. | Battery, display, keyboard, storage, mainboard, data recovery, repair shipping and lost work. |
| Change | Data transfer, banking and identity re-enrolment, number or SIM changes and lost accessory value. | File transfer, application licences, configuration, training, peripheral replacement and downtime. |
Model three outcomes
Expected case
The device meets the task for the planned period, receives support, needs ordinary maintenance and achieves a conservative resale value.
Early repair
A battery, screen, keyboard or storage component fails outside free cover, creating repair cost and downtime.
Early exit
An essential application, support policy, storage limit or changing need forces replacement sooner and reduces resale.
- Use written current prices, not remembered estimates.
- Keep business and personal tax treatment separate.
- Do not count optional accessories as essential without a task.
- Use conservative resale rather than the highest listing seen.
- Include time only where it changes the real decision.
- Recalculate when support or subscription terms change.
Energy evidence is one cost input
The ENERGY STAR computers programme lists certified models under criteria covering efficient off, sleep and idle operation, power management and efficient power supplies. Its current Version 9.0 criteria took effect on 27 October 2025. For covered EU smartphones and slate tablets, the EU energy label helps compare efficiency and battery endurance. Actual energy cost depends on local tariffs and use; do not let a small charging-cost difference hide support or repair value.
Phone and computer cost FAQs
Is a phone contract the same as the phone cost?
No. Separate the hardware price, interest, mobile service, insurance, trade-in and any early-exit charge. Compare the service plan independently where possible so a monthly figure does not hide the device cost.
How should I include resale value?
Use a conservative value for the expected age, condition, support remaining and market, then subtract selling fees, preparation and risk. Also run the calculation with zero resale so the decision does not depend on an uncertain future price.
Does the most energy-efficient computer have the lowest whole-life cost?
Not automatically. Energy matters, especially for high-use computers, but task fit, supported life, software, repair, downtime and replacement timing may have a larger effect. Compare all inputs over the same period.
Continue your device decision
Use the next guide that matches the buying, support, repair, backup, migration, resale or disposal question you still need to resolve.
