A wheel calculator is made of concentric paper or plastic discs, used to make calculations involving time periods. They have applications in pregnancy

Pregnancy

Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...

 (to calculate the due date) and insurance

Insurance

In law and economics, insurance is a form of risk management primarily used to hedge against the risk of a contingent, uncertain loss. Insurance is defined as the equitable transfer of the risk of a loss, from one entity to another, in exchange for payment. An insurer is a company selling the...

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Online wheel calculator

An Internet web site
that may be used for insurance cancellation calculations providing an alternative to the manual paper wheel calculators. The online wheel calculator can be used to calculate all three cancellation methods including pro rata, short rate and short rate (90% pro rata). Also provided is the earned and unearned premium.

Paper wheel calculator

A circular calculator made out of paper and plastic disks that works similar to a circular slide rule. It has a base line that is aligned with the inception date of the insurance policy. An arm on the wheel is then aligned with the cancellation

Cancellation (insurance)

An insurance policy may be canceled before the end of the policy period. This has the effect of ending the policy coverage on the date of the policy cancellation.-Cancellation Methods:Three different calculation methods are commonly used...

 date of the policy. The number of elapsed days, pro rata and short rate factors, both earned and unearned, are indicated by the arm in proper column. The policy premium is multiplied by the factor to calculate either the earned or unearned premium.