How can I prepare new year marketing budget in simple ways?

Check first the last year budget and  marketing plans, make this as a base .then prepare an initial plan then discuss it with the related parties draft it and make final review and discuss with management. then you can prepare the final version for final approval

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First consider the background of last year's performance, therefore you can gauge on how you can make the allotment and proper allocation to utilize the budget well.

Business growth is purely depend on Marketing. Accordingly if your target is high you need more marketing. So, just take some % of sales forecast as total marketing budget. Then classify it in to different heads as required in marketing.

Check first the last year budget and  marketing plans, make this as a base.