Enter your pay once and see it as hourly, weekly, monthly and yearly.
Your gross salary is what you earn before deductions; your net (take-home) pay is what actually lands in your account after tax, national insurance or social security, pension contributions and any other deductions. The gap between the two can be large, which is why comparing job offers on gross alone can mislead. To convert an hourly rate to an annual salary, multiply by the hours you work per week and by 52; to go the other way, divide.
Watch the assumptions. A "full-time" figure usually assumes around 37–40 paid hours a week and excludes unpaid breaks. Overtime, bonuses and shift premiums sit on top and are often taxed at your marginal rate, so a headline bonus is worth less in the hand than it looks. Part-time pay is normally the full-time equivalent scaled by the hours you actually work.
Think in take-home terms. When budgeting, base your plans on net monthly pay, not the annual gross, and remember that a pay rise pushes only the portion above each tax threshold into a higher band, not your whole income. The calculator above converts between hourly, weekly, monthly and annual figures so you can compare offers like for like.