Quick answer
Define what counts before you calculate. Overlapping roles double-count and gaps disappear unless you decide how to treat them.
Two different measurements
Employment duration is the interval between a start and an end date at one employer. It is unambiguous. Career length is the span of a working life, which involves several roles, possible gaps, possible overlaps, and a decision about where it starts.
Because career length is a composite, the answer depends on rules you choose. Stating those rules is not pedantry — it is the difference between a figure that means something and one that cannot be compared with anyone else's.
Use this guide with the right tool: Open the Career Length Calculator for elapsed career duration between start and reference dates. If the question shifts, compare it with the Employment Duration Calculator or the Years of Service Calculator.
Span versus sum
There are two legitimate ways to total a career. The span is first start date to last end date, which includes every gap. The sum adds each role's duration, which excludes gaps but double-counts any period of overlapping employment.
They give different answers and both are defensible. A CV usually implies the span; a calculation of experience usually wants the sum with overlaps resolved. Say which you used, particularly if the figure appears in an application.
Overlaps and part-time work
Concurrent roles are common — a second job, consultancy alongside employment, a directorship. Adding both durations counts the same calendar time twice, which inflates the total.
Part-time work raises a related question: is a three-day-a-week role for four years worth four years of experience or 2.4? Both readings appear in practice. Whichever you use, apply it consistently across all roles rather than to some and not others.
Where the figure is used
Professional registration, experience requirements on job specifications, immigration points systems and some insurance categories all ask for years of experience, and they usually have their own definitions.
Read the definition before calculating rather than after. A figure produced under your own rules and submitted against someone else's is a correction waiting to happen, and the correction always comes at the least convenient point.
Worked example
Try it with the dates in front of you. Where the answer sits close to a threshold, treat that as a prompt to check the rule rather than to conclude.
Common mistakes to avoid
- Adding durations without checking for overlap. Concurrent roles count the same calendar time twice.
- Ignoring gaps in a span calculation. A span includes every gap. Say whether that is what you meant.
- Applying a part-time factor inconsistently. Whatever rule you use, use it across all roles or the total is meaningless.
Use the right calculator
Three tools cover most of what this guide describes. Each shows its working, so a result can be checked rather than trusted.
Frequently asked questions
Which figure should go on a CV?
Usually the span, with the roles listed so a reader can see the structure. Do not present a sum as if it were continuous.
How should I count part-time work?
Decide whether you are measuring elapsed time or full-time equivalent, and apply it to every role consistently.
What counts as the start of a career?
That is your decision — first paid work, first role in the field, or post-qualification. State which you used.